Unfortunately the last time I was in Cancun I was told that Restaurant Los Almendros had closed. Too bad; I loved the place. The new favorite for Yucatec food in town, at least according to me and a few other Flyertalkers is Labna (Margaritas 29, 1/2 block behind Av Tulum).
Details/reviews available on the following thread from Dining Buzz (in addition to other suggestions for CUN dining):
http://www.flyertalk.com/forum/showthread.php?t=407593