Bars in the city for a party?

So my bday is coming up and I'm trying to figure out a place to celebrate my bday.

I'm looking for a pretty spacious bar, not too classy, not too grimy and with a dance floor. I'm inviting a pretty big group of people in their mid-20's so something that would be good for about 30 people. Preferably anything below Times Squareish.

Any recommendations welcomed, Thx