if you want the best gaming card, id say audigy, just a plain oem audigy, ive had a game theater xp before which used the same DSP as the santa cruz, it didnt sound as good as the audigy, (on the same set of speakers).
so audigy. and its future proof with the eax HD.
PS: when i tested the sound card, i used a kenwood demo CD, it didnt sound as FULL on the game theater, while it did sound full and there was just an extra depth or somekind. On the audigy i could hear all the instruments while i couldnt with the game theater, but if you want to save money and you want to get the optical out and crap get the game theater.