Behringer XENYX 2442FX
If you travel a lot or are hard on your equipment, this might not be the board for you. Behringer equipment tends to be a little wimpy, mechanically but if the board is not moved a lot, it would be fine. Mackie is better for heavy road work.
The technical information is a little sketchy but the documentation indicates that it has a USB audio interface. No information about how many channels. The users guide doesn't even mention it. If you are serious, you probably don't want to use this as your primary board but it's a very good backup board.