Nobody I know goes here for the food, as it is quite sub par. The margaritas, on the other hand, are famous around here. "I think they put crack in those things, they're so addictive," is commonly heard. The Rio has a policy of only three margaritas per person, and that it plenty. My policy with the busy bartenders is two, because I might think I want the third, but I never need it.
The music is loud and it's packed on weekends, often with a line out the door if CSU is in session. There are free salsa dancing lessons every Tuesday. It is a classic way to start an evening in Fort Collins. Go before 8pm to beat the lines; it closes at 11pm.