On campus, I was a fan of the short-lived Tequila Cove on 195. Only bar on campus that didn't charge and cover and only bar that had a semblance of an actual bar. As a legally-aged senior, it was an easy walk from Whitney and I particularly loved their $4 40s Wednesdays. It was also the only bar on campus I can recall that had tap takeovers from local breweries.
Back in my early- to mid-20s, I loved Alibi in Fort Greene, NY.
Probably the purest "dive bar" I frequented regularly: cheap, but liberally poured drinks, a diverse "come as you are" clientele, great personable staff. Most importantly, and especially rare in NYC: no pretension whatsoever.
The last time I went there, the entire bar was glued to their one small TV watching the Fierce Five kick butt in the '12 Olympics and everyone was losing their minds.
Locally, I loved and miss Jimmy's Seaside/Seaside Tavern. In high school and college, my band played there about a dozen times and we grew enough of a rapport with the owners that we basically given free reign to show up in any side project our members came up with. One favorite in particular was a one-night only gig as "Party at the Moon Tower" which was basically our original five-piece band with five added guitarists of random friends of ours. Once our band fizzled out, Seaside was also a fun place for their weekday open blues jams.
While FTC is amazing and Capitol Theatre is excellent, Seaside and Acoustic Cafe were the last local music bars in now an extinct Fairfield County local music scene. Too bad.