Here`s some games so you will know what I like:
Adventure Quest Worlds
Dragonfable
Mech quest
If you know any browser games like that,or download able games like that,tell me here.

Try Furcadia.

It isn't exaclty a "game" but it does seem like a game.
The setting is similar to those games you are talking about.

See for yourself:

http://www.furcadia.com