There's a really good breakfast place on E St. in Chula Vista too. Aunt Emma's Pancakes I think. Right off of 5. We stayed next door to it in 2010. This year we are a little farther south.
For those coming from North County, there's an Original Pancake House in Kearny Mesa, right off of the 163, that's excellent (and IMHO, better than Aunt Emma's).
As for Mexican fast food, just look for anything with an "-erto's" in the name. Roberto's, Humberto's, Umberto's...I've even seen a Juanberto's. Believe it or not, they all have pretty similar menus and the food is pretty much the same. Definitely NOT saying they're bad - they're really good! (and the added bonus is that there's pretty much one on every corner in South County San Diego area)
To the poster who wanted to try ceviche - get it from an upscale restaurant. If they're not too clean about it, or they're using cheap cuts of questionably fresh fish, it can give you Montezuma's Revenge, which is not something you want to deal with during Con.