Just spent 10 days all over Quintana Roo. Top 3 restaurant experiences:
1. The Leaky Palapa, Xcalak. Kind of comes as a complete surprise to find an amazing gourmet, casual yet upscale place in this end-of-the-road, way off the beaten path town. (But you do need to know about it in advance because reservations are required.) Run by Canadians, it is not really Mexican food, but takes local ingredients into modern dishes. I had lobster huitlacoche ravioli with squash flower cream sauce, and a phenomenally good bread pudding with allspice sauce for dessert. The chef and manager could not have been more friendly and welcoming. As a bonus, we saw a jaguar on the road on the way back to where we were staying, near Mahahual.
2. Nohoch Kay, Mahahual. This is a scruffy cruise boat port town with a lot of persistent touts. Nohoch Kay is at the far end of town beyond the touts. Fabulous ceviche. Incredible fish tacos for 17 pesos each. That is only about $1.50. I am a big eater and I only needed four of them, they were overflowing with great, crisp, non-greasy fried fish.
3. El Rincon Chiapaneco, Calle Jupiter Sur, Tulum. This place was not visually different from many others in our travels, just a tent over a seating area featuring the ubiquitous red Coke chairs. It features antojitos, kind of like Mexican tapas in that most of the menu is not huge meals, rather small items like tacos and other less well known items such as panuchos. Everything was presented beautifully with fresh cabbage and bright pickled onions. Totally authentic, the whole kitchen is open and you see your tortillas getting pressed and fried as you order them. And the real highlight here is the beverages (none alcoholic) which are constantly being blended right at the counter. All sorts of delicious fruit combinations - I had grapefruit/lime/strawberry, as well as superior versions of standards like horchata and jamaica. We ate here 4 times and really had a hard time going anywhere else. Dinner for 5 (not all big eaters, however) was rarely much more than $20. Seriously, I think few people could eat more than $10-12 here. Plenty in Tulum is more expensive, not sure anything is actually better. Small negatives: noise from blender, drifting cigarette smoke, roving musicians and other solicitors.