At least spell his name correctly, it's Nobuo Uematsu. Anyway, I think Uematsu makes some really great music, and he was composing music for FFs for 15-20 years. Not bad, and I don't think he was getting repetitive. Final Fantasy IX soundtrack, which consists of 152 songs, is his greatest score, IMHO. Lately, Yoko Shimomura has been producing excellent music as well, and her work in the KH series is fantastic. I'm not really impressed by Masashi Hamauzu's work, though, and Yasunori Mitsuda's music only impressed me in Chrono Trigger.

I don't think it's fair to compare Nobuo Uematsu and Harry Gregson-Williams to each other because Uematsu is a video game music composer, and HGW is a movie music composer. I think the latter has done music for some of the Metal Gear Solid games, but I still wouldn't consider him a video game music composer just because of that. HGW has done some really good movie scores, though, such as the Chronicles of Narnia and Sinbad. I haven't heard his Shrek scores, but they're supposedly good, too.