I used to have an ART USB TubeMP, kinda thin and harsh. Right now I just got a Mackie Onyx Satellite and am putting it through its paces. I like it a bit better so far. The preamp is fatter and more glassy sounding. Has a lot more features than I need, but it does run in stereo and have phantom power....
just got the M-audio mobile pre. not terrible. seems to work. difficult to set up for vista, as M-audio doesn't support vista much at the current time.