<< Philips Acoustic Edge
Turtle Beach Santa Cruz
All of the above are based on the CS4630 chipset, and in my opinion sound better than the Hercules Game Theater XP. The XP mainly has nice extras. >>
Um, the Phillips card is not based on the CS4630 chipset (its based upon their own prop. chipset if I remember correctly), but the GametheaterXP IS. And generally the SC, AE and XP are rated fairly close to each other with the more features going of course to the XP. (Can you say breakout box, hehe).
To choose between the three just decide what features ya want. If you want the most features go with the XP, as to the SC or AE...thats a harder choice. I'd say go for whichever you can get cheaper