I had a wonderful stay at Leonardos place. A cozy small place in the center of the city. It has everything what you need and it's just wonderful, also the roof is a great spot to enjoy your coffee in the mornings before you head out.
it is walking distance to all the great spots around the area. There is also one of those bike things, that you find all over the city, very close to this place. I realy recommand getting a pass for those bikes, because biking around Mexico City is just a wonderful experience, plus you'll get very fast from one spot to the other. Also the Park near by is a nice spot to go on a saturday evening, many people gather togheter there and dance Salsa. You go learn a bit how to dance and participate or just watch.
I realy got to enjoy my stay there and I' looking forward to go again.
Oh, maybe a little thing that's nice to know. To get to the bed you have to go up a ladder, so you realy habe to be fine with that.