Well, I personally had to ask myself this question not too long ago and the answer was:
The Dirt Devil DDC1800P (where the "P" stands for "Pet" and pretty much means that is has one of those 99.9% dust filter filters - not that it autonomously cleans your pet's cage every day). There's a pretty picture of it on the right.
Being available at Bunnings, where, as we all know, cheapest prices are just the beginning, probably biased my decision somehow. Anyway, the reason why I'm such a big fan of the product is the following. As many vacuum cleaners, it comes with several extensions, which can be attached to the end of the hose. One of them being the "Turbo Tool":
This fantastic attachment contains a rotating brush, which is connected to a turbine-like part, which is placed in the airflow. Quite clever, I thought. Somewhere is a warning to keep it away from hair. I assumed it meant "hair attached to a body", especially after reading the instructions above, and went away to vacuum the house ...
Unfortunately, that thing does its job very well and picks up pretty much anything on your favourite bedroom carpet (not including the carpet itself! but, for example long girls' hair) and cutting any hair which may be caught in the brush with a pair of scissors doesn't do the trick - well it didn't do it for me anyway. It got to the point where the brush didn't rotate at all, which I did not like.
What I did like, though, is the fact that not only the lid can be removed by the user to provide better access to that nasty hair wrapped around the brush - no, the entire attachment can be disassembled in seconds. The brush and the turbine come out, allowing access to their axles and bearings. That's where I found another 100m of hair nicely coiled up.
All that disassembling requires absolutely no extra tools. The "locking ring" is a rubber ring which just rolls back, and from there on everything just pulls apart. Very nice! 10 points for user friendliness!
