I think driver support is very important so I tend to stick with companies known for their support.

My home studio computer has the M-Audio 1010LT audio card which is rock-stable and does everything I need. I also have a Novation X-Station in my studio which can operate as a USB audio interface but it has problems with Intel 915 chipsets so I mostly use it with my laptop when I work with Reason and other softsynths.

My new laptop had really bad sound (hissy and low volume) so the first thing I did was get the Creative Labs Audigy 2 Z5 Sound Card for Laptops (PCMCIA) for it, which is fairly cheap: about $75. It's excellent (great SNR: 104db) and it comes with some great software. I haven't used it for recording though, only playback.

I also have a Tascam US-122 that I've used for recording and it's very stable. I've recommended this to friends who love it and use nothing else. Sells for $199.