Shark - Shark Navigator® Pet Pro Upright Vacuum with Self-Cleaning Brushroll is the easiest to assemble vacuum I have ever used. 
This vacuum has an incredible filtration system. I have seen zero dust puffs in using it. The Shark Navigator Pet Pro preforms incredibly well. Easy to navigate swivel head is the perfect size. The self cleaning roll brush actually stays clean. The collection tank is a good size and easy to use. This vacuum has a sliding dust brush on the crevice tool that is beyond handy! I can not sing enough good praises for this vacuum!!! I highly recommend it!!! I have long hair cats and this tackles the hair with ease!!!