http://www.clubcrawlers.com/toronto/events/
scroll down, and click thursday, and check out events. I recommend going to an event on Thursday nights as opposed to just randomly picking a bar/club as not many people party on Thursday night (they have work friday morning). Keep in mind girl ratio on weekends is usually better than during week days, but still shitty, therefore going to an even should produce a decent girl ratio.
I did go to Century Room on a thursday once. Yes its a nightclub, i realize the stigma behind it, however it was somewhat tolerable, we got there super early so got in for $10 cover (others later on in the night had to pay $20). Beers are $6+, one floor, one dance floor, surrounded by booths. If you get there early, you're allowed to sit at a booth even if it is reserved, until people who reserved it get there (which they don't till midnight or so). Smoking patio is cool, especially these days, you won't suffer much and i was opened three times outside when i went for a smoke by 8s/9s, not bad. Music sucked later on in the night, the DJ there is an idiot, hope they got a better one. At first he played some house/electro, some good top 40 remixes, then started sucking, cutting good songs short.
Oh yah, one more thing if you do decide to go there, i found bartenders there to be "friendlier" than any other place, so try to chit chat a bit with them when you get there early, let them remember you a little so that it gets easier for you to get drinks when it gets packed later on.
This is a general rule of thumb anywhere you go actually, build some rapport with the bartender, especially if it was a guy bartender. Its harder to do so with a girl bartender especially in Toronto as she will lump you with the category of "another drunk guy, pre-drank too much, trying to hit on me cuz there are no hot girls around yet", but it is still manageable if you hint that you're from outta town, that sort of thing.