There are many games like Clubpenguin which you can play without subscribing or paying any money.
Moviestar Planet; You can live your dream as a moviestar, hang out, and have a boyfriend.
MechQuest; Here you get to play with robots. First you create your character and choose the colour of your mecha.
Trollz; Here you play to gain Troll, and then you can spend them at the mall. A cool place to hang out!
Tibia; This is a game mixed with magic and mastery. You can go, hang out, play and make more friends.
Poptorpica; This is a more of virtual fun game that you should check out. You can customize your character after it is "born”.
Zanpo Virtual Cities; This is a special virtual city game with most of the characteristics of a real city. You can become a citizen of a city, build your home like in real life and become the mayor of your city. It is a 3D multiplayer game.
Habbo carries most of the qualities of ClubPenguin. You don’t need to run any installation; it can be played right in your browser. The game is made of a virtual hotel where people create characters and chat with other real people.
There are still other games you can play for free online but people value and frequent Miniclip.com. Miniclip is an online database of free games among which are action games, sports games, puzzle games, games for girls, games for kids, flash games and much more. Maybe this is the reason a lot of people like miniclip; it is a collection of many free games. You can create your own game avatar with clothing and accessories to represent you and then select Miniclip games.
You can also play league games with your friends and challenge one another in scores. Though it requires registration you stand to benefit from high scores, rankings, leagues, friends list, news feed, your own avatar, awards and much more.