Cafe Montmartre has been described as very "New York lounge-like". A lot of people dressed in black. Somewhat pretentious, very cool nonethelesss. Drinks are expensive but worth it. Great place to start the night off, or spend it too.
The bands are usually pretty good.
It is a somewhat small bar, but you can normally find somewhere to sit. There is an attached smaller bar called The Sidecar. Same drinks, same waiters. The only difference is that sometimes the Sidecar is reserved for personal parties (very fun).