A.H.
My friend celebrated her 40th at a really fun place in Chinatown -- Yakatori Boy -- which is a swanky karaoke bar. You can reserve a private karaoke room, and they have rooms of various sizes depending on how large your party is. There's a big flat panel TV, two mikes, and you run the karaoke selection yourselves, singing and having fun, while staff bring you Japanese appetizers, sushi, and drinks. We had an absolute blast. I plan to have a party there for myself someday!
http://www.yakitoriboy-japas.com/