Well, call me what you will, but if you are willing to pay for music then I’m sorry… BUT, I’d recommend FF-Origins anyway just because it is the only way I could stand to play Final Fantasy 1 again, and it was a damn good re-play at that (the music was really nicely remade).
The Resident Evil Apocalypse Soundtrack really isn’t all that great, and I really didn’t like the Green Day albulm, so I’d go with the Final Fantasy one.
Origins. What it boils down to is this, if you dont have Origins, you should get it just to have. It’s a damn great remake of the classics and belongs with all final fantasy fans. Xenosaga is good, but certainly not rare yet, and will most likely drop in price before it becomes hard to find, so yeah… Go with Origins.