I think I'm just gonna stick with FFXI. Still haven't come close to playing through all of the story material, plus based on the stuff I've heard about XIV I have a feeling I wouldn't like it anywhere near as much as XI.
It's to do with the fact that MMOs are not designed for using a controller - they're designed to be played with a keyboard and mouse, and you really do need those in order to be able to play one.
Funnily enough FFXI happens to be the exception to this rule. Aside from using a keyboard for chatting and stuff, the game's designed entirely to be played using a controller, and using the keyboard and mouse makes for some very awkward controls. The vast majority of people who play it on the PC use a usb controller and completely ditch the mouse for that very reason.