Don't want to come off as a spammer or some bot but these two sites have free mmorpgs to play. I wouldn't say so huge of a player base on either but they're sort of ultimaesque. Dransik takes some getting used to and I just find it hard to play without getting bored.
euo isn't bad but its more of just a pure grindfest.
Never played tibia but heard about it.
Again, most mmo's lack in content so take what you will of a time passer or combat type game with chat features.
euotopia.com/
www.dransik.com/
www.tibia.com/