A friend and I checked out La Palapa (St. Marks near 2nd Ave) on Saturday night, based on the recommendations on here. The menu was great. I don't think I have ever seen such a large selection of interesting and varied Mexican dishes. This was clearly not going to be a chips and refried beans kind of place.
They tried to sit us in a very small and airless backroom and accomodated us when we asked to be moved to the airy (and exceptionally noisy) front room.
Nice selection of frozen margarita flavors. I had a tamarind (good) and a hibiscus (not as good). The margaritas were not very alcoholic -- at least, I did not get hit with my typical post-margarita slurring.
We split an appetizer of the special squash blossom quesadilla. Nice and mellow.
I had the cod in pumpkin seed sauce, which was a huge piece of fish in a nicely prepared green sauce. It came with rice (nondescript) and swiss chard (undercooked, to my taste). The best thing we had was a side dish of chayote, which came in a slightly spicy cream sauce. I had never had anything like this before and I would recommend ordering it. My friend has a couple of margaritas and had the duck in mole sauce and seemed to enjoy it but did not rave.
My primary complaint was the service. Admittedly, it was a crowded Saturday night. But it took quite a while to receive our food and people around us who arrived after us received their food 10 minutes before us. The waiter was nice, but overworked. Total price with tip was around $110.
I will definitely go back on a slower night and order some of the other interesting dishes on the menu.