There really is no "best" one, it's whatever suits your needs.
Personally, I have been using 1-2 Delta 1010s for about 6 years now and have never had a problem with them. I started using my buddy's Firestudio/Digimax combo for awhile and liked it a lot, but it got the red light of death recently so he's a convert to the Delta 1010 now. This is a good option if you don't mind using PCI, but if you want Firewire I'd still recommend a Firestudio, as the preamps sound good and (assuming you don't get a lemon) the hardware is very stable with Windows (though the Delta is even more stable). I would allocate a separate budget for an interface aside from your computer budget.
That's assuming you mean interface by soundcard. If you mean just a plain soundcard, here are a few ones that
look decent
M-Audio Audiophile 2496 - Never used one but have heard lots of good things about it. Sets you up with basic two track recording capabilities assuming you have a mixer to use
HT Omega 7.1 - Your basic 7.1 card, but with optical in/out (which you may or may not have a need for)
M-Audio Fast Track Pro - What I personally use at home. Provides latency free input and output, very very stable, an all-around great little interface if you're willing to spend the $100 or so more than a regular sound card. With my system it works fine, but I guess it would really depend on if the USB on your motherboard has problems or not (which would be a rare occurrence as USB has, for the most part, gotten its bugs worked out)
Here you have lots of choices too. Fun, eh?