Mexico City is a great city with a lot of culture.  It has some great hotels, I like the Sheraton Maria Isabel located on the Paseo de la Reforma.  It is a very nice hotel with a great lobby bar and spacious suites.  Make sure you have a couple shots of Don Julio Silver while you are staying there.  The hotel is walking distance to Zona Rosa, an area with lots of restaurants and bars.  Make sure you stroll along the Paseo de la Reforma to see the Angel and the Independence Column.  If you get a chance, venture out of town to see the pyramids (sun and moon).  It is very cool to climb them but be warned they are steeper than they look.  Another great place to visit is the Zocalo (big square) surrounded by the Metropolitan Cathedral, National Palace and the Temple Mayor.  The Cathedral is an awesome site!  It is sinking slowing so you see lots and lots of work being done on the structure. Right off the central of the square is an ancient ruins that was discovered under the city.  It turns out throughout history each culture basically build upon itself.  Make sure you pick up a souvenir or two at one of the outside markets.