We were there for three days and were mostly disappointed with the food and the prices, especially after a week in Merida.
Trecelunas - breakfast.
We stayed at their hotel and the breakfast was great. Lots of people come for it with good reason. Reasonably priced, flavorful, great chorizo, etc.
Don Cafeto - in town. Worth going, slightly less gouging than the places near the beach. Chilaquiles in red sauce - generous portions, flavorful. Also good coffee.
El Tabano - This was the best meal we ate in Tulum, but it was not as great as we expected after reading reviews.
Yes - the albondigas w/tamarind were very good. Yes, the wine was excellent.
However, The service was atrocious. I had made a reservation for New Year's eve through the Todo Tulum website and had a back and forth with someone who was very nice, complimenting me for communicating in Spanish etc. We got there and found that they had "forgotten" our reservation - because the guy who I had made it with (Diego) had never communicated with the rest of the restaurant staff about it. so we had to wait....and wait.....and wait, first to be seated, then to order. so it went.
They forgot an ingredient in our salad (anchoives) and they never brought us dessert. I would not go there on a busy night.
Casa Banana: I read reviews of this place on Trip Advisor. It is not worth it. lunch cost $500 pesos - and that was for an appetizer, a sandwich and fish tacos, one juice and one water. . Yes, the fish was perfectly cooked but everything was *totally bland*. What an expensive disappointment. My fiancee suggested that it was the sign that Tulum's food had been ruined by European tourists who can't eat spicy food.
Mateo's - outside our hotel. We went there twice. The first time, obviously, we enjoyed our food. I had a very nice grilled chicken and salad. My fiancee had a grilled vegetable fajita that he really liked. The second time we went it was really bad -a taco platter that consisted of three tacos that had no condiments, no sauce, and very little meat. We felt ripped off and disappointed.
El Mariachi - on the North beach. We went there looking for Don Cafeto, which has now closed. It was OK - more flavorful than Casa Banana, but that's not saying much. At least each dish was not over $10 USD.