"Great Mexican restaurant" and "fun place to go" are mutually exclusive concepts in old town Scottsdale. For the latter category, go to the Old Town Tortilla Factory on Main west of Goldwater. Sit on the gorgeous patio and enjoy chips and salsa with a margarita. Those two items are the only things worth getting, everything else about the place just plain sucks. If you want great Mexican food in the Old Town area, you are completely out of luck. Every Mexican place in the Old Town area is pedestrian at best. Your best nearby bet is Los Sombreros on Scottsdale Road just south of Thomas.