I put Celtic, Egyptian and Amerind. Of the three that get taught regularly in the states (Norse, Greek, and Egyptian), I think the Egyptian is the most interesting. Norse could be a decent choice, since you essentially have a few families with a lot of adventuring going on. Amerind could get difficult because of variations from one region to another. I stayed away from Hindu because of the number involved.
Something that could be very useful is treatments of the oriental religions, since Oriental Adventures was a little sparse there.
Something that could be very useful is treatments of the oriental religions, since Oriental Adventures was a little sparse there.