Medievia was the first mud I ever set eyes on, and it will probably be the last. This mud has everything a mudder could need.

-Great Atmosphere
-HUGE Area's
-Weather Effects
-Dragon Attacks/Lairs
-Multiclassing
-Hundreds Of Skills
-Trade Run's to earn money
-Rideable Dragons/Horses/Ships
-Clan Towns
-Clan Wars

The list go's on and on..
You'll just have to check it out yourself.

http://www.medievia.com

Happy Mudding

Not a big fan of browser games, but this one looks fun :D . It also seems like it has a somewhat large community.

This is no browser game! It's a mud, you connect to it through your telnet client or MudMaster 2000 or any other mud client and play it on a screen full of text in real time, no sitting in firefox at a website refreshing the page waiting for the next turn.