Don't forget the tamales! I love me some tamales.
I went to Cancun, Cozumel, and Merida when I was a kid and I don't recall there being such a drastic difference between "real" Mexican food and "American" Mexican food. It's a little different in Mexico, and it's really good, but it's still food for the poorest of the poor. It's not like the gap between Italian food and American Italian food, where the entire culture is completely different. Things like meatballs on spaghetti, cream in carbonara, pizza made with dough instead of pasta, "alfredo" sauce and how fettuccine alfredo is something that no Italian would touch are stark differences between the two cultures. Mexican food isn't that much different...it's better and worse in some places in Mexico, but it really does suck here, at least in Italy. Italians are so delicate and anything more than pepper is too much for them, so their Mexican dishes typically blow. Chinese food is the same.