Online simulation, chat and communities where your can build and dress up characters!
Inf 
Create a virtual Inf (information elf) and teach her to chat so that other infs can talk to her! Nice!
Habbo Hotel PG-13
A virtual world where you can hang out in the cafes, restaurants, swimming pools and games rooms. Or create private rooms and your own party.
Pico
Create your personal cute Pico, make friends and earn money to change your outfit and decorate your room! You have to be very social to earn money in this game.
goSupermodel Java Applet
Design your own super model look, go on photo shoots and score points for jobs well done.
Woozworld
Create your own avatar, your own universe and chat! Earn money by finding jobs and making achievements!
Doll and the City
Doll community with really good graphics which focuses on dress-up and make-up. Playing for free is limited but you can still have a lot of fun!
Fashion Fantasy
Design your own line of clothes or be an owner of a fashion store!
Dizzywood
Create a character, walk around Dizzywood, collect coins to buy clothes and other items, play games, chat and have fun!
Tinier Me
Dress up your SELFY avatar to have fun and chat with other members!
Fantage
Set in the future when everybody travels on hover boards! You can play games, earn stars, go shopping and chat!
Poupee Girl
Poupée is French for "doll" and here you get to dress up and have fun with your very own doll. It takes time to get to know this site but it's well worth it!
Millsberry.com
A virtual city game where you can create your own character and explore Millsberry town through his or her eyes!
Honeyz Web
Create your own girl and dress her, feed her, groom her, play games and create a look book!
Club Penguin
A kid-friendly virtual world where you, as a penguin, can waddle around and interact with other players. The game is free, but the dress-up feature is only for paid members.
Pandanda
Get your own cute panda and earn coins to buy clothes and furniture for you tree house!
Poptropica
A virtual fun town to explore! To customize your character make sure to click on "change character" after your character is born.
Secret Builders
After creating your avatar you can explore the world of Secret Builders, do quests, keep a home and other tasks!
Whuddleworld
Create your Whuddletar and explore the fun, colorful Whuddleworld!
Zanpo Virtual Cities
3d multi virtual cities where your goal is to build a block that will fit into one of the cities! Patience required!
Whyville
You really have to be patient to earn your face parts here, but it is fun!
Babydow Virtual Baby 
I really like this one! Adopt a virtual baby and take care of her until she is three years old! Sometimes difficult but very fun.
Barbie Girls
Design your character and your own room, invite friends over and go shopping at the mall!
Spark City
You can customize your own character and choose and color clothes but the apartment is my favorite spot!
Garden Party World
Creates a character and grow your own garden where you can grow strange things like toys, clothes, pets and furniture!
WeeWorld
Create a WeeMee avatar and have fun with her in WeeWorld!
Super Secret
Age your character from a ten year old to a teenager in this game. The more you play, the older you get and you can buy clothes and other stuff!
Small Worlds PG-13
A huge community where you design own avatar, dress it up and design your home. Go to the public spaces to hang out and chat with other users!
GirlSense
A large website with lots of fun dress-up and makeover activities to do, I recommend starting with exploring "My Boutiques", "Fashion Ave" and "Salon"!
Yoobot
Buil a yoobot with your face and make sure he or she stays healthy!
Nicktropolis has been taken off-line.
Pixie Hollow Disney Fairies
Start by creating your own fairy, decorate her house and have fun with the other fairies!
Diva Chix
Dress and style your own diva, battle against other divas and have fun. I'm so hooked on this one!
My Diva Doll
Create your DivaDoll, shop and train her for a dream job in fashion or entertainment!
MinyanLand
Play games and hang out while you learn to manage money. But be careful, just like in real life you can run out!
Zwinky Cuties
Dress you Zwinky Cutie, chat, make friends and play games! Cute graphics and fun games but the free account is very limited.
Dragon Fable PG-13
Build your character and battle monsters, find treasure, and much more!
Total Drama Island
Have fun with the characters from the Total Drama Island cartoon!
Primp Me iLook
Make your own avatars, select ready made outfits or make your own, talk to friends, write blogs and vote for other members.
Primp Me iToon
Same features as above, but here you can create an avatar that is more anime/cartoon version of you.
Student Survivor
Two games where your goal is to create a student and keep him or her alive and happy! You have to register if you want to save your game.
Happy Meal 3.O
Customize your avatar and your tree house, go on quests and have fun!
Show Jumping
Choose a color for the horse and clothes for the jockey, then start your training!
MoiPal PG-10 Java Applet
Create the Pal of your dreams with a home of your choice. Important: I have only tried the web version which is free!
RuneScape
An adventure with monsters to kill, quests to complete, and treasures to win! Very popular.
Meez PG-13
Create an animated 3D version of yourself and use it on blogs, websites and everywhere else on the Internet.
DressUpChallenge PG-13
Use the Makeover Creator to do dress ups and makeovers, enter challenges and vote on makeovers others have done. Lots of fun!
Stardoll MeDoll
Create your own MeDoll (to look like you or someone else), go shopping for clothes and accessories and meet friends.
Crash Village PG-13
Sign up your own character and help Crash Bandicoot fight evil villains!
= the very best of the best!
= recommended websites.
= only works in Internet Explorer.
= requires registration.
Simulation