Barcade is big on local/regional brews and usually has a cask. They've been successful enough to open a 2nd location in NJ.
Rattle N' Hum isn't much to look at but you can't argue with 40 taps, especially when there's a tap takeover (i.e. 40 beers from someone like Victory) or special event (I caught the East Coast v West Coast IPA Faceoff). Service is notorious, though, and the food is reputed to be hit and miss.
MCSorley's is more for atmosphere than beer, and that atmosphere's not a million miles from an Irish pub. Beer's only OK, and available in bottles everywhere. Place does have history, though; and just down from Burp Castle.
Not been to Gingerman.
In the East Village/Lower East Side, d.b.a has a good list, though they're more beer snobs than beer geeks, and Spitzer's Corner has a good range too, and should be less crowded than usual with NYU out for the summer.
