Roberto's is a staple in my life. I can get a hefty meal at a reasonable price ($5 for a bean and cheese burrito with lettuce and pico de gallo). Their burritos are filling and perfect after a long bike ride or run. I also like their salsa bar. Though the salsas are far too hot for my white-girl tastes, I fill up on carrots (yes, they are HOT, but I grin and bear it), cucumbers, and radishes before I dig into my main meal. That way, I've had my fill of healthy vegetables and I have burrito leftovers for a snack later that day or the next.
My sons love the cheese quesadillas. They are basically heart-attacks-in-a-box--a carb/fat feast that is absolutely delicious.
Some of the employees (and many of the customers) don't speak English so you know you're getting authentic Mexican food.