I am a fan of all things Sangria, and Firefly has to have some of the best around. I love places with a great happy hour, atmosphere, and patio. Firefly has all three plus great tapas. The service is always fantastic they are very attentive and friendly. I can't think of a better place to start off a weekend in Vegas with your friends than this place.
The must haves for me when I go is of course the Sangria (red) and the stuffed mushrooms with chorizo and chicken. The Calamari is quite good, and on my most recent visit the Shrimp a la Diabla was fantastic. I look forward to my next visit to Firefly which will be very soon.