GuildWars

Supposedly an MMO. Plays more like a co-op (or solo!) RPG if you're not into player-versus-player, because of instancing everywhere that isn't a safe zone.

AmberYust has an NPC named after her.

There is/was a Mudd guild named Rhinos Run at Three Fifths C. It is/was generally made of awesome.

See also GuildWars2.