As someone who has given Coco's a try many times to my continued dissapointment, I have to recommend the ritas at Luna del Mar in Seagrove.
By no means was I stating that CoCo's is known for the "quality" of their margaritas. It is the "quantity." In my opinion, the food is like most mexican food in the US, with the exception of Texas, and lower CA. Everywhere else is "mostly" crap. You go for the chips, salsa, cheese dip, Margaritas and friends, maybe the live Salsa band. Nothing else. The atmosphere at CoCo's is nothing special, but that is not as important as the people with whom you dine. Did I mention that CoCo's is open for business year-round? It is hard to get a margarita at a closed bar. Maybe, when Kurt gets the Block Party all set up, we could have a Best-Margarita contest. I will gladly be a judge, and it sounds like we already have a few bartenders willing to submit their entries. I make a mean Margarita myself, but I know what mine taste like, so I will glady sip on your recipes.
As for Luna del Mar, the Margarita are great. The food, well, I have eaten there several times, and it is hit or miss for me, although I know many people who think there food is great. I guess that since I know what authentic Mexican food tastel like, I cannot get excited about anything less.
Oh, and they're closed until Valentine's Day for the off season.