Well here's my list.
I reread your post and added a few games. I left the others there, just in case though)
Adventures Unlimited:
Cool game. Theres a nice RP community there as well as quests and stuff.
au.betterbox.net:5000
4 Dimensions
This game is pretty fun. I played a while ago and enjoyed myself. I might head over there again, since I see they have player housing. I didn't to any RP when I played, but I think there is a nice little RP community there.
4dimensions.mud-puddle.net:6000
New Worlds:
I liked it here. Nice players and staff. There's global chatting, a nice backstory and nice RP. This game has levels, but you get XP from RPing. One guy I talked to says he's never slayed a mob and he advances very nicely.
Shadows of Isildur:
A very nice RPI which is level less, of course. You can be anything from a cook to a warrior, whatever. I highly suggest, especially if you are into Tolkien's works. No global chats, but very helpful staff, help files and player base on the forums.
middle-earth.us:23
Shadow Seige:
Another good one. When I play, I think of SoI with global chats. Very relaxed RP. Its level-less and classless. Lots of crafting, magic and demon! Also a nice backstory about the last surviving city after a cataclysmic event. I don't think its on TopMuds list though, but you can find info on the site or on MudConnector.
shadowsiege.com:4080
And my favorite:
Armageddon:
Fun, but harsh. There's no global chats, but a very helpful community on the discussion boards and a list of helpers that you can email or IM. There are crafts, hunting and more. Check it out.
ginka.armageddon.org 4050