Buy It! Honeywell HPA200 HEPA Allergen Remover Air Purifier, $165 (orig. $199.99); amazon.com
To catch larger irritants like dust mites and pet dander, a purifier should have a HEPA filter, which can theoretically remove at least 99.97 percent of dust, pollen, mold, bacteria, and any airborne particles with a size of 0.3 microns, according to the Environmental Protection Agency. The Honeywell Allergen Remover does just that, and since it also comes with an activated carbon pre-filter that takes on gases and odors, it s especially great for homes with pets. At 20 inches tall, it has a suggested room capacity of 310 square feet, so it s best suited for large areas like living rooms, main bedrooms, or even entire studio apartments.