Margaritas is a big Mexican place on County Line Road, right nwext to Red Hot & Blue. The atmosphere is good and the drink prices are cheap, but the food is about the worst Mexican you'll find.
It isn't bad, necessarily. It's just comletely bland. The cooks there don't add the extra ingredients that make Mexican food delicious - peppers, onions, etc.
The drink prices are pretty good. I think 36 oz. beers run about $4. The drink that the restaurant gets its namesake from is pretty run-of-the-mill.
Margaritas is popular because it's centrally located, big, and because the atmosphere is fun and attractive. Just don't go there expecting good Mexican food.