My parents have always made beergaritas, and I haven't ever tasted a better margarita. Honestly, not even Mi Cocina or Gloria's.
Here's the recipe:
6oz frozen limeade
6oz (or more) beer of your choice
6oz (or more) tequila of your choice
We buy the small cans of limeade that are 6oz, which makes measuring super easy.
Dump the limeade into the blender, measure the tequila and then beer in the limeade can and dump those into the blender. Then fire up the blender and slowly add ice until its a creamy icy concoction. I'm drooling just typing this.
If you want to get a little crazy, tip a mini Corona into your marg and you have a Coronarita! Yum-o!!!