i got 2 games you can try.
1- pawngame.com this is a 2D, low graphics, multiplayer game. U run around shooting other people. Its fun, simple, easy to get better at. But because its a 2D, low graphics game you will probably get bored from it. I only play every once and a while now and thats because im just naturally pro in this game.
2- runescape.com this is 3D, med graphics, mmorpg. This game is fun because unlike pawn, there is just about always something new to do (unless ur me)
you can play free for as long as you like or you can pay around $8.00 a month for extra features (like a 3x larger map, awsome minigames, new weps and armor, new quests, so on) (i wouldnt buy membership right away since you will have no idea what your doing (there are like a million new items you can get, plus everyone is a higher lev and it makes minigames boring)
there are lots of skills you can train in, so on. Whats really fun is after a while (NOTE- when i say a while im not talking about a total adict while) you will know this huge map by heart and how to get around, you will know all of the items and were all the monsters are, so on.
There are also updates at least once a month, they add new skills, minigames, so on, and it makes it almost impossible to get bored.
the only real down fall is if u have a slow computer, the game might start to lag when there are lots of people on screen (MIGHT) also when loading after an update it might take a while (5 min) (but dont worry, after you load an update it will load fast until a new update comes out)
if u join this game add me ( 123456789518 ) and i can help you out a lot.