EQ2 is hands down my favorite MMO (I've got 5 level 90's)
I think my favorite part is how easy power leveling is
If you have a max level fighter (bruiser/monk/sk/paladin/zerk/guardian) you can power level a new character to 90 in a day. Go figure the only mmo out there where fighters are the best power levelers?
It sticks to the tank/dps/healer mentality though and its hard to fill a role outside of your classes designation (mainly because people would rather not compete for loot so they wont bring 2 tanks in a group)
If you like playing a tank the game is -awesome- tanks in eq2 are one of the most fun classes to play, they do pretty great DPS and in pvp/solo pve they are fantastically OP.