Although Fred's isn't home to the most gourmet Mexican food in town, it definitely is the best Taco Tuesday destination. I've never been to the Gaslamp location, but I've been to the Old Town and Garnet locations more times than I'd like to admit. Once you fight for a table (or sometimes even a spot to stand) you can get three margaritas and four tacos for ten bucks. Go early for a prime seat near the salsa bar.. or else you'll be juggling your margaritas and fish tacos all night long.