This store in downtown Tempe has everything "Sun Devils" that you need. I stopped in here for some shirts for my brother, and they had a large selection: guys, gals, little ones. Various sundries are also available for the hungry college students...boy, I remember those days!
The prices were great on the merchandise -- I'd planned to get only one shirt but ended up getting two. The guy at the counter was very nice. If you're looking for Arizona State U merchandise and apparel, I'd stop here before going to the school bookstore (which is probably more expensive).