My favorite tour is any without a bus load of tourist. I kid you not about this story. The first time to Mexico my fiance and I booked a apple tour to Chicken Pizza, lol, and on the tour a Canadian Mother asked "Where did the Mayans get all the square rocks to build the temples?" I said the same store the Egyptians got theirs from and her son walked around kickin rocks saying, this isnt square enough.
Went to Tulum last trip and took the colectivo and a private tour guide.
Interested to go on a tour of Coba but not sure if my wife will book with PDC tours or not.