AT
Not to steal Craig's thunder w/ Tascam, but the new(ish) UH-7000 is pretty darn good. Not the greatest low latency drivers - about 12 ms in/out on my system, but I haven't tried to tweak it either. Other than the drivers, it is a really high-end unit. Excellent conversion and stellar preamps. Clean, but sweet. I doubt if I'd pay $600 for conversion - it is better but not by hundreds of dollars. Even budget converters are really good. But combined w/ the preamps it is a really stout-sounding unit and you don't need external hardware to make recordings that play w/ the big boys. No midi and stereo only, but it is very good.
I try to resist the temptation to hype Gibson Brands products here, but the UH-7000 really is top of the line in terms of audio quality. They're marketing it as a stereo mic pre, not just an interface. If you compare the specs to anyone else, you can't help but be impressed.