I don't go here for the nightlife, so I can't speak to this place as a bar. As a lunch place, though, it's fantastic. There is always a place to sit, the service is fast and friendly, and they have a great menu that leans slightly towards the southwest.
Their southwestern quesadilla with the cajun chicken is amazing. I don't usually like things with corn, roasted or no, but the whole thing is delicious and not laden with grease. The grilled tortilla is flavorful, as is the side cup of southwestern sour cream they give you to dip each bite in.
Other good eats are their onion rings, Cobb salad (and it's under $9--cheap by my book), and Buffalo chicken.
Bottom line, I dig Guido's.