I've had a Dyson DC3x (can't remember, but current version of it is DC39, canister for houses with pets) for 4 years. It works really, really well. I'd buy it again if it broke tomorrow (and I'd get the DC39).

I also have a handheld DC34, and I am happy with it too. I'd have no complaint if the battery lasted just a bit longer (it is ok most times, actually, after 2 years, so I admit I'm being picky).