Bar Fly, downstairs from the Valentina in Polanco, can be a riot if you're in the mood for some Latin dancing with an older crowd.
El Estribo inside the Hacienda de los Morales, literally ‘the stirrup bar’, has one of the largest selections of tequilas anywhere (over 300).
In Polanco, for a younger crowd, there is La Martinera (5281-7238), which is a chic and fun, with a good martini menu. This bar is closed for the time being, though it should re-open within a few weeks.
If you're looking more for the New York black-and-white look, there's the Rexo (5553-1300, 5553-5337), also in the Condesa.
A very chic new lounge bar right next door to the Plaza Condesa cinema at the junction of Tamaulipas and Nuevo Leon, is the Cinna Bar (5553-0438) which offers a very cool, Manhattan-ish atmosphere, with music played at a very manageable pitch, and some decent food, though it's always crowded.
Also in the Condesa is the ever-popular Barracuda (5211-9346) offering live music on weekends, some nice food, and a hip crowd.
Further uptown, the Cosmo (5281-4631) is a minimalist bar/club on Masaryk that offers acid jazz and house music.
If you prefer jazz bars, there's Jazz Upstairs (5592-6114) in the Historical Center, and also New Orleans (5550-1908) in San Angel.
If you're looking for an authentic Irish pub, The Dubliner is a pub/restaurant that has just opened in Anzures/Polanco, on Mariano Escobedo 434 (5250 8105). They serve Guinness beer on tap and also have pretty good pub food.
El Mitote (5211 9150), a small tapas bar in La Condesa, exudes an extremely friendly vibe. Owners Alejandro and Walter make a concerted effort to greet customers with a fraternal manner, and by your second visit, you literally become a regular. The music is an excellent combination of acid jazz, soul, and samba; however, the volume never gets intrusive and the lights are kept low. El Mitote's success is really one simple formula: long night drinking and discourse away from the dredge of a noisy nightclub. Amsterdam 53, corner with Sonora, Colonia Condesa.