I'm sure any New Yorker who goes to shows has been here but I couldn't help myself to review it... The Bowery Ballroom. I know people who have mixed feelings about it, but I love the place. It's located on the corner of The Bowery and Delancey Street so it's prime location via subway and close to Brooklyn (Williamsburg Bridge is like 5 streets due east down Delancey).
When you walk in you immediately go downstairs into a basement bar that's a decent size and perfect for mixing and mingling pre-show. The dim lighting, underground look (hey, you are in a basement) kinda give it a cave feel. Then you go back up some stairs to the main ballroom with the stage. Not quit street level though. It's all general admission; no assigned seating so you can wander and continue to mix and mingle like you did at the bar. Should you get tired from walking around there is something of a mezzanine that goes up on both sides with seating, although it's very limited. It's like a half lounge and there is a bar up there as well so no need to leave the show to get a drink.
It's a small and intimate venue, don't expect to see the Rolling Stones there. I have been there mostly to see They Might Be Giants, who some of you may or may not know of. It's such a small place that I've actually gotten to talk to the Johns (both the members of They Might Be Giants are names John) after the show as if they were just other patrons.
If you're not going to a mega, blockbuster type show and it's a smaller, more personal band, then check to see if they're playing at the Bowery Ballroom. If it's TMBG playing, then I'll probably see you there.