Typically in Mexico we bring a taco station in and have tacos al pastor. These are beef and/or pork tacos from meat cooked on a rotating spit. They are amazing and fun to watch as they are made. It is a show in itself. See Ricky Martin on this video make some tacos!!
http://www.youtube.c...feature=related Watch Ricky Martin as he tries to prepare some. It is in Spanish but in minute 1:30 you will see a pro do it:).
The other favorite is quesadillas which is the tortilla filled with cheese and meat and of course all kinds of salsas. Chilaquiles are fried corn chips boiled in sauce and are excellent plated and served on a late night buffet. They may be marinated and served with spicy red or green habanero sauce. This will kill the buzz for sure!
My personal favorite are the tacos and they are so easy to set up. After having tacos I recommend brides to offer a Mexican coffe station where the guests can enjoy cafe de Olla (made in clay pots) or flammed coffee with brandy and some sweets that will make their toes curl with delight. It is fun because we serve it table side and it becomes a bit of a show and it helps to kill the buzz as well. Unless of course they spike the coffee with tequila, ay, aya ,ay!!
Enjoy your time in Mexico and try different things, if not, what is the point of getting married in Mexico? Besides getting more value for your money of course.