We have a very large air purifier in the main house, and a smaller one that is still in the box (months after buying) in our bedroom. Partly to catch cat fluffs, and partly to clean the air of allergens (pollen) and forest fire smoke. The big one fills up with cat hair. Two ragdolls are a lot to deal with when it comes to fluff.
The big air purifier is a Livepure Bali. It's great (though one died on us and we returned it--so we're on our second). HOWEVER, getting filters from the company that makes them was an issue and we have offbrand ones. Not sure I would get it again knowing how hard it was to find new filters.
The boxed one is a Winix from Costco. I think it works well because my dentist and my optometrist each have one in their treatment rooms, but I can't say for sure. It'll probably not come out until the air turns brown again from forest fires.