M-Audio (Score 1)

M-Audio makes several good options in both PCI and external boxes. If you're looking for PCI, try the Audiophile 2496. It gets good reviews.

Personally, I have an Omni Studio system and have been extremely pleased with it. The audio quality is excellent.

Notably, M-Audio has also been much more forthcoming with OS X drivers than any other company I've seen.