Affordable and just outside of town is the Vibe Hotel, pay a little extra and you can get an amazing river view.
Wotif have specials there all the time. I've stayed there a few times. It's nothing flash. They have 'studio' rooms which are self catering style with a king bed and kitchenette and a sofa bed. not great with parking though.
It's on the edge of town, but not in the centre of it all, walking distance to Cavill ave, bus stop right there for themeparks etc.
Or Broadbeach is great too. There's loads of hotels, and there are a whole bunch of nice restaurants, near malls and also on bus route to sufers and themeparks.