Dyson. The latest model has just been released (6 years in development, watch TVSN if you want to know it all). I am drooling over the new one, I so want it. I have had two Dysons in the past 15 years.

Biggest tip, get all the tools you can with the model you choose. An extra $50 now, can save a couple of $100's later when you realise you do want the dusting wand etc