I frequent Modern Margarita weekly. It's a very nice addition to City North and the Desert Ridge neighborhood. They have a great ambiance going on inside and I love their patio--best misters around here.
Guacamole-legit
Salsa Flight- good with unique & smoky flavor
Tacos - I've had the carne asada, pork & shrimp, all have been superb.
Drinks- you'll find any tequila you could think of behind the bar. Their mojitos are excellent and one of the female bartenders makes an outstanding mojito with a pineapple twist (can't remember her name).
Moscow Mule- reason enough to head to Modern Margarita. THEY KNOW HOW TO MAKE ONE. And it is served in the traditional tin mug!-- a concept most phoenix bars can't quite grasp.
Last thing, Sunday is all day happy hour. What's not to love here?