GF= boring after you get to lvl 60
shaiya= pvp based game, but it's a mmorpg, which is weird lol. i know a bunch of ppl that quit that game cuz it's hella boring lol
perfect wrold= ... i hate how KIDS save the damn world... so lame and over rated lol.
LoL= isn't a mmorpg but it's pretty fun if you like not lvling up/powering up besides with runes and such. the good about this game is that you can use many different chars and kill alot of minions, and work with others to win. out of these 4, i'd say LoL is the best, even tho it's not a mmorpg.
if you want a aeria mmorpg game that has many things to do at all times, i'd say play 12sky2

i hope this helps

ps. i never even heard of the others besides fiesta.... but dont get me started on that lol