M-Audio makes a lot of good stuff, with their usb FastTrack line being quite common. A couple years ago I used their Firewire Solo which I thought had a nice warm sound through the headphone output. M-Audio has been known to have issues with drivers though, although I haven't tried their stuff with Win7.
Echo Audio makes some nice gear for firewire, though it's been a few years since I've used any of it. I do remember liking the sound from their gear more than M-Audio, although they cost a bit more as well.
I currently have a Focusrite Saffire 6 USB which I reviewed here: http://www.head-fi.org/forum/thread/472484/review-focusrite-saffire-6-usb
So far it has been the most stable (in terms of drivers) audio/recording inteface I've used.
The best thing to do is head down to your local guitar center and see what they have available. Then shop around for the best prices online and get your local store to price match, in case you ever need to return it. From my experience, getting recording gear to play nice with your software and other hardware is tricky. Sometimes you just have to try a couple different ones until things work.
Edited by Armaegis - 11/28/10 at 10:25pm