If home cleanliness and air quality are both very important to you, then you should take a look at Shark's Vertex Upright vacuum cleaner (model AZ2002). It uses a HEPA filter to keep 99.9% of dust and allergens inside after they've been sucked up, and it's a completely sealed system that keeps all that crap from spewing into the air while vacuuming.

Some vacuums do have HEPA filters but aren't sealed properly, so the stuff you're vacuuming can't even reach the filter before flying out of the canister and into the air, making it a next-to-pointless feature that exists purely for marketing purposes.

The Vertex Upright is a powered lift-away vacuum as well, so the canister pod can be removed from the main body of the vacuum, which is helpful in two ways:

1. It helps the vacuum body reach further beneath coffee tables, couches and the like.
2. It can be carried around completely independently of the main body, essentially converting it into a cordless vacuum that can better reach high-up spots, more easily clean stairs, etc.

The “DuoClean” mentioned in this post's title refers to the fact that the vacuum head sports both a soft brushroll at the front and a set of PowerFins behind it, a combination that not only picks up more dirt than you thought possible, but also allows the vacuum to switch seamlessly between carpet and hard flooring and do excellent work on each surface.

All these features and more are the sorts of reasons why you should stop buying cheap vacuums. Budget vacuums don't have this kind of versatility, they don't clean as well, and they certainly aren't keeping your breathing air clean. The Vertex Upright, on the other hand, is an investment you make for the sake of home cleanliness and your family's health, so I'd say it's worth it.

The same guy from that Vacuum Wars channel I just linked above reviewed the Vertex last October and had almost nothing but positive things to say about it:

If you watch that guy's other videos, you know how picky he is about these things, so that was all the endorsement I needed.

Get the Shark Vertex Upright for $429 on Amazon.