the best sound card for games would have to be the Creative Sound Blaster X-Fi Elite Pro, but costing around £250 its a little pricey...
I think you can get very high quality sound for only a little bit of money. Most soundcards are highly overrated. This has been proven with both the Audigy 1 and the Audigy 2 (I can tell you from personal experience -look at my computer-) . My advice for you is to go with one of the following: 24-bit 7.1 surround (Turtle Beach) http://www.newegg.com/Product/Product.asp?Item=N82E16829118104 24-bit 7.1 surround (Creative Labs) http://www.newegg.com/Product/Product.asp?Item=N82E16829102177 I would personally go with the second one only because I have used it in the past and worked out great for me. In fact, it is still in the computer and still works great.
emu10k1 is a good chipset on that 2nd sound card fred posted i too had a Live! but it's demise was most likely my own fault
Creative Sound Blaster X-Fi Xtreme Music ^^^^^^^ thats a good one, and its only £100 @ overclockers.co.uk