m-audio audiophile 2496 and audiophile 192 are the m-audio boards to look at, for stereo output
x-fi prelude is a great board, pricey though, and like hyyam said, not worth it for stereo output (unless its your only choice, or you love EAX)
x-meridian is just unreal quality, a comparable board is the HT Omega Claro Plus (roughly the same board, in terms of features/specs, meridian is a touch better, but claro plus is quite good)
Asus' Xonar D2X (not the D2, the D2X) has great figures, comparable with the Prelude and X-Fi Elite, as well as better support under Vista, but its PCIe (this may or may not be good for you)
Elite Pro on its own, is just overpriced for what it offers, basically
and the prodigy's proper name (seen it like 4 different ways in this thread alone):
Audiotrak Prodigy HD2
and its around $80 (and very hard to find in the US)