I needed one for my new iPod, and browsed the selection at newegg. I think the only differences between the are number of ports, whether there's an "internal" port, whether there is an external power connector, and of course which chipset it uses.
I shy'd away from the VIA models (because I'm biased against VIA, YMMV) and bought the cheap-o model from newegg with the NEC chipset. No drivers needed in WinXP and it has worked great so far.
I love being able to transfer mp3's at 4MB/s.