La Plaza Bakery & Cafe in Soledad. I have no idea how my parents found this place, but I no one in my family passes by without stopping. The tortas & burritos are to die for. Simply the best carnitas I have ever ate. Despite the location, the inside is always spotless and the help gracious. The bakery items are irrestible too! Just take the Soledad exit (any of them will work) and follow the street straight through town. La Plaza is about half way through town on the east side of the street. If you keep going straigh it will put you right back on 101.
It depends on what kind of Mexican food you like, but sure, I have some suggestions in the Paso Robles area. Papi's is my favorite for good, cheap Mexican food. They have excellent tacos and quesadillas. The carne asada is grilled in tiny little bits and is very flavorful (and I hardly ever order beef!), the rajas con queso is outstanding, and the carnitas melt in your mouth and is a bit sweet. To get there, take the Paso Robles exit (I think that's what it's called. It's the one after Spring Street when you're heading north), go straight to the signal, which is 13th Street. Turn left, go over the highway overpass and up a block or two to Pine Street. Turn left on Pine, and Papi's is right there on the right-hand side. They have some tables outside.
Another great Mexican place is 4 Hermanos. They serve what I gather is more "traditional" stuff. The tacos, for instance, don't have beans or cheese or rice in them. Very flavorful and hearty food. All my friends love it, and I think it's tasty, too, but if you are a picky meat eater, beware (I like my meat pretty--boneless, no skin or gristle, etc.). To get there, take the Spring Street exit and go straight on Spring Street (most people will be turning right to go over the bridge. Don't follow them) until 6th. There's a signal there. On the right you'll see a strip mall, and 4 Hermanos is in there.
There are other delicious Mexican places farther up north towards SF. Melanie Wong has posted some good information about Salinas, Greenfield, etc. I do know there's a La Fogata in Greenfield that's supposed to be good. I ate at the Salinas one, and it was really tasty (it's also an interesting, weird place where you can order your Mexican meal in Japanese!).
Mexican Restaurants in SLO:
IZZY Ortegas Mexican Restaurant - 1850 Monterey Street, S.L.O., CA 93401 (805) 543-3333
PEPE Delgados - 1601 Monterey Street, San Luis Obispo, CA 93401 (805) 544-6660
Petes Southside Cafe - 1815 Osos Street, San Luis Obispo, CA 93401 (805) 549-8133
Tortilla Flats - 1051 Nipomo Street, San Luis Obispo, CA 93401 (805) 544-7575
A new one opened recently in SLO . . .
Milagros (meaning "Miracle") opened for business on August 30th in downtown San Luis Obispo in the space formerly occupied by Carl's Jr. Offering authentic Mexican recipes in a unique atmosphere, Milagros's menu is composed of made to order family recipes from Guadalajara with a special emphasis on seafood dishes. 698 Higuera Street, San Luis Obispo, 805-596-0307
re: April McLaughlin
In SLO on Nipomo Street is a little place called the burrito wagon. There you'll find very tastey, fast mexican menu items. The "wet burrito" is the best! It's any burrito off the menu you prefer , smothered in a savory mild red sauce, then topped with all your favorites like guacamole, sour cream fresh salsa cilantro and onions. It full of flavor and filling.
They have everything from their most popular tri tip burritos to the super veggie burrito that is really loaded.
I eat there at least once a week. you'll enjoy it i'm sure.