haha this comming up on the frontpage is ur luck. posting this in a rift specific subforum means u will get that as the best game =)
Rift was good in beta but got wrecked when they started making it more like wow and still requireing a monthly fee (this wasn't a problem back when it was different from wow and not bound by the classical this class have to do this concept)
Swotor might have the worst playfeel I have ever experienced and felt like it was done without checking if it was sluggish.
Wow is old needs a clean slate have done so many things right but now they changed and can't go back.
So overall I feel wow is the better game even if I can't stand what have become of it and if I had to play one of them I would play rift (if I ignore the people I know playing wow)
Obviously World of Warcraft, just for it's past, owns the rest.
SW seems to have been a failure for what the fans say.. and GW2 about the same. The problem is that WoW has evolved for so long that it's got all the MMO stages you'd like to have from a game. So we can certainly say that it won't be easy to beat WoW.. nothing new there.