Ourworld

Good things: 

They have loads to do.

It is fun.

Easy to set up and straight into game.

You meet new people safely.

Mostly everyone is nice so you feel welcome.

Customize your character with a huge selection of clothing.

Decorate your own room and garden.

Bad things:

You get bored easily.

Can get laggy at times and slow.

You need to be a member to do most things and have more fun. 

They try to get you to pay for things using real money.

Some people can be mean.

Link: http://web2.ourworld.com/ow/?env=home

Dizzywood

Dizzywood is a basic game for all ages, you can do anything that a basic virtual world has, explore, dress up customize to make your life perfect.

For all ages.
Great for finding new friends.
No need for membership, you can do most things without it.
Can get boring easily.

IMVU

Very popular social game although it is a download it is well worth it and of course the space it takes up is only little, you would have to have a windows or ios mac computer for this to work.
This game is a great game for 13+ explore the detailed virtual world dress your character with some really great styles, pose for the camera and show them off in unique albums.
Get married start a family or just party all night long.

Membership is required for certain things but only for create and some actions.
Game is very addicitve.
There is loads you can do without membership.
You can do anything you want fight love play explore you name it.

Moviestarplanet

Moviestarpalnet is a unique online world that has millions of players join every month and what's even better is they have new updates fairly often so you are guaranteed a good time !!
Loads of options to become a unique celebrity, climb into the world of fortune and fame star in your own movies and create fab art in your at book.


Some things you need to be a V.I.P for, that can also mean that you will not level up fast.
Very welcoming to new comers.
There are great welcome gifts to.
Very entertaining.
Gets boring when you run out of money.

WARNING:

(Just thought it would be important to warn you)

Sorry if i scared you, and please take her advice.

Stardoll

Stardoll is a really great games mainly for girls, collect awards customize your doll decorate your suite with millions of options, and stardoll update regularly so be prepared for even better gaming. Plus new to stardoll play the academy missions and win cool prizes.

Better with membership.
Can carry on playing for hours without getting bored.
Things added regularly.
Great chance to meet friends.

Ekoloko

This is a very unknown world, but i think it should become more popular, Ekoloko is a great online world design your character just how you want to,
Millions of games for you to challenge yourself to, why not make new friends and learn the secrets of the island.
Customize
 your own hideout just as you want it.

Hard to get a username.
Great fun for about an hour...
Not much you need a membership for.
Popularity is growing hugely.

Mall world

Mainly a girls game as you can imagine, you can do anything without membership.
Social and fun !! Share awards an climb the ladder of success to try and make you ultimate dream shop !

No membership.
Always great deals.
Sometimes takes long to sell your items.
You ave to wait for your stock to be delivered.

Animal Jam

Animal jam is a really great online virtual world and even better you may even learn something along the way !
You can:
create a unique animal character, shop for clothes and items for your den, you can also meet new friends and complete missions.

You need a membership to have pets and wear most clothes also buy most furniture.
Set a play time timer, have more then one character using the same account even without membership.

a code for 1000 extra gems: Explore2012 - still works in 2013.