It's small, it's difficult to find, but it's awesome. Cafe Pacific has some of the best Chinese/Asian food I've had anywhere. Don't order off the medium sized menu. Ask the owner (P.C., I think he goes by) what's good. You won't be disappointed. You can find at the northwest corner of Prince and Campbell (there's a Safeway and Burger King in the same strip mall).
For those of you with an interest in Tucson cuisine, please patronize this place and tell your friends! It does not seem to be doing well, and I would hate to see it close like so many other underappreciated eatery's in Tucson.