avoid the casino clubs man.. all the girls are ugly. seriously casino is the only place where people don't really get knocked back... so it's kinda an all-comers venue.
wednesday night if you're determined to stay in the CBD i recommend Mai Tai, it's a cocktail bar on the corner of lonsdale and russell street.. then a few hands of poker at the casino.
thursday night... as stated, uni night.. so start at one end of the CBD and drink your way to the other
some notable decent clubs include: Eve on City Road, and Billboards (average, but cheap and lots of girls lol)
if you're still standing after that, hit up Charlton's.. it's a late-night pool hall in Chinatown somewhere.. a bit hard to find but ask around and someone will point you in the right direction.
Enjoy your stay