The good, the bad...
I have a certain affinity to the margarita. I like lime and the taste of tequilla. Over the years I've ordered a margarita (on the rocks with salt, not frozen) everywhere from Bangkok to New York. It didn't take me long to realize that there is a huge range of quality in what passes for a "margarita". While watching various random bartenders make my drink I quickly concluded that there are about a million different ways to make the margarita (and, frankly, some are terrible).
Thus began an informal quest to find a "good" recipe. The result? The recipes at the end of this webpage. I hope you like them.
Before I tell you the recipe, though, let me address the mixes. Some are pretty bad (the bucket o' frozen margarita is terrible, in my opinion) and some are ok (Margaritaville and Mrs. T's). The best I've found is El Paso Chile Co.'s Margarita Mix. But all of them turn out too sweet, in my opinion.
So without further ado, here are the "best" recipes I know. They both makes a margarita in a pint (16 oz.) glass (because, really, who wants a margarita served in a martini glass?!)
Preparation: rub a lime along the glass rim then dip the glass in salt to coat the rim. Add ~4 ice cubes. Don't water it down.
Tequilla influences the taste of a margarita greatly. If you use really cheap stuff then it will taste bad.
The Fresca (or Sprite) adds a bit of a fizz to the drink. I threw this into the mix after someone recommended light beer for the same reason (adding fizz). The beer made the margarita taste funny though. Don't overdo it with the Fresca though: I've found that any more than about 1 oz. is too much. If you don't have any try plain soda water instead... just a splash or two.
I think Grand Marnier tastes better than Cuantro... both of which taste better than Triple Sec. The problem is that around here a bottle of Grand Marnier or Cuantro runs ~$35 while Triple Sec will set you back about $5.
The purpose of the Roses' Lime Juice is to add some sweetness to the mix -- if you skip it you will end up with a drink that is too sour. If you have no Roses' around then I'd suggest using simple syrup (heated water with disolved sugar in it) If you think the recipe ends up too sour just increase the amount of Roses' (or sugar).
For a twist, add about 0.5 oz of orange juice or cranberry juice. Like the Fresca, though, don't add too much -- any more than ~0.5 oz and it will take over the drink.
I've recently become partial to the "Italian Margarita" which goes something like this:
I'd love to hear about any other recipe refinements you come up with!