CoX, i play both sides often, pretty much a lifer at this point (3 years and counting)
tried a few others.
DDO: is good, launcher stopped working and friends moved on
Requiem: like it for the bloody nature of the combat, side that, its like WoW, in that, there is a LOT of grinding, the possession beasts are cool though
WoW: tried it, twice, to see what the hype was about and saw absolutely no reason as to why its so popular, with the point less violence against local wildlife, and while i understand the good stuff is at higher lvls there's gotta be a hook to make you wanna get there, and stabbing wild cats and pigs for 20+ lvls is just no.
CO: during a 1 year rest from CoH i tried this, and ... its interesting, they do combat right, far better then any other MMO i've tried, and power selection, also good, you allowed to try them out before their made permanent an you have to pay to remove them. problem is, ranged powers are the way to go, end of story. and theirs no real reason to team up as of my last playing.
PW: pretty, but grind fest like no other