I am very sorry to say that I have never played a Final Fantasy game or anything related to it. I'm even sorrier to say that I haven't listened to his work...well kinda.
I do have some MP3s from the Game Music Concert series. Nobuo Uematsu made these arrangements of his original compositions. So, I have heard some of his work, and what I have heard, I very much like.
Because of this topic, I'm listening to what little MP3s I have and I'll give you a decision later. But, the one that I can think of off the top of my head (because I like it so much) is Final Fantasy IV [Ending Theme] from the first Game Music Concert.
EDIT: I was mistaken. Uematsu didn't create the arrangements, just the original compositions. Either way, it's still his work (I suppose), and I still like it.