New Years at Ramon's (last year) was the most fun I've had at NY in my life and I'm planning on going back this year. We slipped over to Iguana's afterwards and I partied until 6 a.m.
Even though it poured rain for half of the evening, the band kept playing and hundreds and hundreds of people kept on dancing on the beach in the rain. You had to be there to believe it.
Don't wait around until you absolutely have to go to the washroom though, go early, go often.
The lineups are horrendous! hee, hee