I love Montreal, but as other have said, mid-week is fairly dull in the evening. Things do get fired up Thurs.

IMO, Sky is fun because it tends to be a fairly mixed (age-wise) crowd and the different floors provide a lot of options. On a nice weekend, the roof deck is a great place to just chill and have a cocktail during the day.

Unity did open back up after the fire last year and was extremely busy on, both, Friday and Saturday nights when I was there a few weeks ago. On Saturday, it was defiantly a much younger (early 20s) crowd. I'm always impressed with the music there and have a ton of fun (pop floor upstairs, hip/hop or r&b downstairs, depending on the night)

Parking is more leather-friendly, but I would not call it a leather club. Large club with club/trance music upstairs, and a mix downstairs in the "garage". I'm typically not into that crowd, but have been there many times and had a good time. Would not recommend wearing Abercrombie and Fitch T-shirt there. I think it is straight a few nights during the week.

Stereo gets a lot of big DJ names is is owned by David Morales. This used to be more of an after-hours place, not sure if it still is anymore though???

Of course, the strip bars: Stockbar (mixed types of dancers), Taboo (younger twinks), L'adnonis (mostly twinks), Campus (mixed).

Enjoy! it's a great city.