I believe that FFX is one of the better FF games...the best, by FAR is FFVII. It follows the story of Cloud Strife. I will agree with what the Uchiha kid had to say. Sony and Nintendo are AMAZING at making KILLER games...however...those great games are few and far inbetween. Zelda...AMAZING series. KH another great example. Metroid (never a personal favorite until recently), and duh Mario. the Final Fantasy games only reached my radar at FFVII, and I believe that FFIX was CRAP.
There are FEW good games for the X-box...but you could just as easily get the games for ur PC. and getting them for ur pc (unless you have a piece of junk like I do) is much more cost effective then buying a whole new $400 360 for MULTIPLE mediocre games.