I'm not generally a Four Seasons fan but I like the one in Mexico City and stay there every time I go.
It's pretty cheap by FS standards and generally has some good specials running. It's very gay friendly (in my experience at least) and has an excellent concierge.
They often try to sell you an upgrade to a suite at check-in but the standard rooms are fine. It also has a nice garden which is quite peaceful by MEX standards
have fun. It's a great city to visit