There's nothing I love more than a late happy hour -- and by late I mean 10 PM. No bar should be allowed to claim they have a "happy hour" and serve $4 domestic beers from 5 PM - 7 PM.
Here are some great happy hours that not only last until 10 PM, but also have super awesome drink specials:
Keybar (East Village) - 2 for 1 drinks. Daily. Great beer selection
Verlaine (Lower East Side) - $4 lychee martinis, $3 beers. Daily. Great specialty drinks.
Boxcar Lounge (Alphabet City) - 2 for 1 drinks. Sun - Thurs. Cute outdoor garden.
Three Of Cups (East Village) - $3.50 drinks. Daily. In the downstairs lounge.
No Parking (Washington Heights) - 2 for 1 drinks. Daily. Gay bar.