The best Margarita all depends on the quality of ingredients
That being said, saying any Agave will work will not always lead to a great Margarita
You should specify which liquors you have personally tried and suggestions for folks who are unfamiliar with Tequila
Also, Cointreau in place of Triple Sec would be a must
I would also throw a shot (or half) of some Grand Marnier and some fresh Blood Orange juice, spectacular Margarita
Simple, though, as it should be