In SD: Oretegas Bistro for Mexican is a must in the Hillcrest neighborhood (close to hotel village, zoo, etc). Casa Guad. is good for touristy Mexican, but if you want something legit...
hey google works:
www.ortegasbistro.com
Also, go to the padres game...nice stadium and inexpensive to boot.
last year they had a dog+peanuts+drink+cookie combo for 5 bucks....sold on the first deck behind 3rd base.