In Brisbane, top three for three very different styles of shows...
1. The Tivoli. Probably the best venue IMO (easily the best indoor) - holds around 1200-1500 full, great vantage points, awesome setting, decent bars, great atmosphere. Good for all shows.
2. The Riverstage. Doesn't work for all shows, being an outdoor natural amphitheatre which fits in around 10,000 people. But throw a couple of bands which can work a decent crowd, like The Cat Empire, and it's sensational when the weather's good.
3. The Zoo. Best place for intimate live gigs - only holds a few hundred or so, but absolutely top notch.