ohioguy12 saidI'm not sure what's going on New Year's Eve, but when I was there a few weeks ago, it seemed like Sky, Parking, and Unity were the best clubs there. They are all in Le Village. I stayed in Candlewood Suites, it was nice and in a great location. Have fun, I personally loved Montreal.
This is mostly true. Unity, Parking and Unity are the three "must" of the Village, but there's a plenty of other places you can go.
There's also this new club that opened 2 weeks ago, it's called "Apollon". I've never been, but there's a lot of hype around it, and it's apparently one of the most beautiful places in the Village.
And when you're in town, just go on this website (http://www.nightlife.ca/quoi-faire), and they are pretty much up-to-date with what's going on in the city (gay and non-gay) ;)
ahem, Unity, Parking, and.... Sky?
can't say I've been to Parking in a couple years, back at its old location, when it was so much better. Last time I went there I was practically molested by several very creepy people, and have not returned. Unity, I have only been to twice, once was last New Years, it was fun... crowded. Sky is my favourite, they have different music in different rooms and on different floors, more variety, and quite a variety of people too.