Legends of Excalibur is the best mud I've ever played. It has a rich environment for roleplaying, exploring, hacking, slashing, leveling, becoming the strongest in the land, et cetera.

28 races and 16 base classes. With dual and triclassing options of either becoming a more advanced form of your class or an entirely different one, along with 500 levels to attain, you have TONS of possibilities to play as, as well as great diversity among other players.

As for questing, there is no place better. LoE has a kingdom based quest system to gain points towards buying the best equipment in the game, money, or training points to improve your stats. It also has dozens of area quests, giving you awesome equipment, and providing lots of challenge and fun. And don't forget quests given by order, clan, and kingdom leaders to gain rank, and any other quests people may give for... whatever.

If player killing is your thing, there are plenty of other PK players, and a great clan system for team competition and raiding. Not so violent toward your peers? Orders take the place of clans for the more peaceful people, and have competitions, and are just plain fun to be in.

The immortals and elders are nice and easy to work with, and there is always some sort of cool RP thing going on with them. So come on, join one of the four kingdoms, fight in the wars, and shape the future of the lands!