I can't pick a single favorite sim, but my favorite household to play at present is my hippie commune, the Dinglewood Ashram.

Currently three inhabitants, brother and sister Shaggy and Sunshine Rogers, and Shaggy's girlfriend, ex-townie Mary Allen. He's romance, the girls are respectively popularity and knowledge.

They're all sloppy, nice, Grilled Cheese-secondary nature-lovers, and I let 'em have free range most of the time. (I fix routing problems, etc.) They make money by farming, both from legitimate organic farming, and from, uh, "other" farming (money trees, in a stand-in role). Regular jobs are for the Man, man. The place is built and decorated with the more bizarre and useless items from the windows, doors, and decorative catalogs.

Eventually they will open a business; possibly a restaurant, as there'd be enough adults, and Mary has both 10 body points (which I hear is good for waiters), and 4-5 cooking points.

The place is full of groovy vibes.

(Yes, if they get a dog, it will be a great dane and I will name him Scooby-Doo.)

My favourite sim at the moment is Sally Riley from Belladonna Cove. She's just grown up to a teen and I gave her the knowledge aspiration, which seemed the most fitting as every 5 minutes she's banging out a tune on the piano or painting. I gave her a cute little light brown bob, some freckles and she just looks absolutely freaking adorable!
That said, her father Timothy is an absolute pain in the rear. Everything he does just seems to irritate me, and he generally just wastes his time sleeping or whinging about something. Or causing fires.

My favourite sim is Smoke Baudelaire. That is because her story.

As background information I play several "make game harder" hacks on. Everything possible is made harder in my game and stories are real. In return for making game this problematic I use jealousy fix (only for married/engaged/going steady), and aging on/off. This suits me good because on the other hand I play also families that I don't care that much, to keep them in time, so I wouldn't either want lifetime hacks to my game.

Smokes mother

Everything started when I was viewing my neighbourhood and noticed I needed sims who would enjoy coming parties and having multiple romantic adventures, I didn't want either one of them to be flat and slutty without any own personality. Each one was gonna have her story.
Vicky was cute short and light haired young woman with heart shaped face, green-blue eyes, love to nature and ambition to become rich one day. Quickly I started to like her and adobted her to my main focus. She started with wealth aspiration, and was going to have romance aspiration later in her life when she got some better time and money. She was supposed to travel alot and have fun with boys.
I moved her in one of camping trailers at Belladonna coves slum area to keep rent tolerable with higher bills, harder promotions and lower salary hacks. Vicky loved to build daisies and tulips with flower table, paint and collect bugs. I gave flower bouquets as gifts to dozen friends I she had made so far, and she was working hard.

The accident

One day Vicky woke up early in the morning and was very lonely and bored. She had often low mood or low aspiration and it was real challenge to make her proceed and have enough money to cover costs of her living. This time she really needed a promotion to be able to pay her bills in time. Exceptionally she had work as late as at afternoon, so I waited until morning 7 clock and guided her to her closest neighbour. They were just friends but they had top relationship, and two attraction points out of three possible. Although Vicky didn't have her romantic second aspiration yet, I suddently got an idea to make them go bed together as one way to fill their needs for fun and social.
Anyway, Vicky would be soon over the worst. Before she would rush to random romantic adventures, felt logical her first one would be somebody closer to her from her old life. Later she would simply move out, start new life somewhere else than in slum, and forget their one morning romance. So they gone bed, done in bed what two adults usually do, slept together hour or two and sent Vicky to work happy and good mooded.

Accidents followings

It was just one time and chances of pregnancy are small in my game, so I didn't suppose Vicky to be expecting baby with random NPC friend, until I saw her vomiting and thinking it. I decided to use pregnancy time for developing her first business. Without promotion bonuses and child coming there was pressure for Vicky to start working for another job anyway. When baby was born, she already had level 1 flower shop with +400 simoleons gain in total - half of their rent and very needed money.
Baby had gotten Vickys bright custom made skin, but since NPC dad was black, it was little bit darker and smoky tone that I would never have chosen for my sim myself. I was in hurry to focus the mother so I just named a baby to Smoke and continued game play.

I didn't think I would play her after she moved out and gone university, and I was going to play her mother mostly as she didn't exist. Next day Vicky simply asked NPC neighbour to look after Smoke and gone work as nothing happened. Baby wasn't causing any big efforts to mother, and took time before I realized to set aging back on. I noticed Vicky was coughing sometimes, but she had been ill many times because food poisoning or work, and recovered too so I was used to it.

More surprises ruining my plans

I hadn't noticed that Vicky had had fatal illness already during her pregnancy, because I had blamed the pregnancy for all the energy loose. Suddently, after coming back from work, running her company for whole night and returning home for sleeping, she got up from her bed and died. It was real shock. I had already been "affected" to Vicky, and now when mother was away from taking my attention, the daughter got it. Ironically enough, Jessica Peterson who was only sick sim at lot and probably killed Vicky to disease, inherited Vickys flower shop after she died.

It was Smokes first birthday, but she hadn't even aged up yet and wasn't any playable alone - what I would do with a single toddler and 400 simoleons anyway, even somebody helped her to age which ofc wouldn't happen. There was premade old couple from my neighbourhoods sim inventory, that I hadn't played yet at all because no life in family. I usually don't enjoy playing old couples without kids. Solution seemed obvious - I picked up the baby and moved whole new family to nice small house.

Felt good idea that they got something to do beside travelling around: a baby and 400 simoleons, which wasn't alot in old couples approximately 60 000 simoleons fortune. That way Smoke Baudelaire ended up being grown up and travelling with random NPC couple, without any other living relatives than his random NPC dad at Belladonna coves slum area. Nowadays she is my favourite sim. :lovestruc

In the end if I had noticed Vickys fatal disease earlier, I would for sure have cured her with more rest. I hadn't realized she had been sick critical 10 days, because Smoke was coming. So on a way I traded one sim to another by accident, but it's lucky I got even Smoke left.

Sorry for the 1-month resurrection. Just wanted to give my opinion.
My favourite Sim is definitely Stella Terrano from La Fiesta Tech (university neighbourhood). She's pretty and very intelligent.
I suggest you guys to play with her, she's amazing

I can't pick, too many... But the latest surprise was Daniel Pleasant. He was one of the last sims I decided to play in the Uberhood because I always hated him and kept laying it aside. Now I love him! He's not that bad, he has many good points and can behave nobly, I just never gave him a chance!

Mary-Sue left him, the daughters left home, Daniel moved in the maid and then kicked her out when she got pregnant. I hated him at that point. Then he moved in a lowly pick pocket Marisa Bendett (not that he knew she was into thievery). I still hated him. One day Marisa got caught and paid all her hard-earned money to get out of prison. Daniel was furious when he learnt that his woman nearly robbed a bank! But instead of kicking her out he decided to give her a chance: she got another job and stayed. He moved out instead and bought two new houses for his grandchildren, furnished them, prettified them beautifully. At the end of his life he made up with both of his daugthers and had many outings with his six grandchildren. I don't know why or how, but he developed triple bolts with Mary-Sue at the end of his life, but by that time she was remarried to a hitman, so I didn't risk having Daniel win her back

That said, when I said that he behaved nobly, I meant that he allowed Marisa to keep all money she earned to herself (and yeah I kept a tally) plus everything she earned with her investment perk, which was a lot. She's just shy of 7000 from earning 100000 simoleons right now, one day before turning elder. At first I wanted Daniel to be mean and insist that the money was half his, since he let Marisa live at his house. But he didn't obey my command, I don't know why, he turned out to be better than that and she kept everything

Sarah Rossi, the zombie cow.

My favorite WAS Desiree Maronchet, a little girl who ended up being surprisingly interesting and awesome--especially considering her parents were losers (they got divorced the very first sim-day I played them because they both kept flirting with the neighbors and then slapping each other when they caught the other flirting, so it was just easier to split them up and move one out) and her grandmother was a kook (good witch who spent all her free time exercising)--she pretty much ran the household, as much as a kid could, and did it more successfully than her parents/grandmother were.

Then our computer went kaput, and I lost 'em all.

My favorite Sim in my game is Superman, seen here. This first picture is a thumbnail of the character. Clicking the picture will show you a detailed look at the character's uniform (with a blue background). I've made some improvements on the detailing, such as wrinkles on the base layer shirt and pants, along with less color saturation. The cape is missing, though. It's a work in progress.

I'm very biased towards my first family, the Yangs. My absolute favorite Sim ever is the eldest child, Alice Yang (red/white dress). She grew up so beautiful in my opinion. She went to college with 5 scholarships, partly thanks to her overachieving parents.

A very close second is Alice's twin sister, Emma (blue shirt). Equally skilled, again thanks to their overachieving parents. She's a Popularity sim while Alice is Fortune, so she takes her studies a bit less seriously than her sister.

I love them both because they're the first Sims born in my game, and they just happen to be twins! It actually took a LOT of trying on their parents' part. After a few days of trying and failing, I kept their parents in their vacation home in Three Lakes and made them try 4 times in a row in the heart bed until finally Ellae got pregnant. I remember thinking Y U NO BABY??? Poor Michael must've been pooped.

Premade Sims, I love Justin Cleveland. I think he's hot lol. First time I saw him as a young adult, I legit went WHOA.

Right now, Samantha Ottomas is my favorite sim; normally it's one of the Curious siblings that catches my fancy. (hey, they're freaking handsome!) But Samantha has such a lovely face, she makes a great mother in my game, and since its the family I'm most drawn to currently I just can't help it. Dora was second in line for me, but since her passing I've grown about five times more fond of Sharla. Peter, a decent looking man, comes in third. Tommy in fourth. I just love the Ottomai.

Right now,my favourite sim is Jennail Tricou.I don't know why i like her..maybe her gothic style is the reason.I love Tricou's because they are kind of mysterious.And their house is awesome xD

My Tom Mison's Ichabod Crane sim (I finally have it right. Thanks to paysitesmustbedestroyed I have the hair I was searching for). When I get pictures I will submit in the proper forum. He's handsome and fun and all the lady sims seem to like him as much as they like Don.

I totally agree, clan Tricou is great!

My favourite sim right now is Sharla Ottomas. As the middle child she was always kind of a loner, but by choice. My Ottomas family is very supportive and loving, so they accepted that Sharla needed a lot of time to herself and the parents even took her on a vacation, just the three of them, once.
Recently she went to college and moved into the biggest dormitory, because she felt that she could live in anonomity there. Unfortunately at this college two greek houses are warring and every student is expected to pick a side and "fight" for it´s honor. But she doesn´t want to, she just wants to be let alone and get good grades!
But all this drama taken aside, Sharla´s lifetime want is becoming Poseidon´s right hand (wo)man. That´s why I styled her like a pirate and I love pirates, so her look probably endears her to me a lot, too.

I have only one favorite. Lilith Pleasant. She is stunning, her face looks smarter beyond her age (along with Angelas), and I wish I had as many opportunities as I can give her to get out of her unfortunate situation. Love forever. She has elven roots and combined with the Elixir, she will live on literally forever, even through unfortunate brushes with the hazardous Downtown, where she ran away, its cold and vampyres.