The Shark Hp202 Air Purifier MAX with True HEPA is the best one on the market. It has incredible power to purify. First off, it has a sleek look making you think it costs much more than it actually does. It captures 99.8 percent of all dust and small particles in the air. The front panel shows the air quality, and it will adjust automatically when quality lowers It covers up to 1000 square feet, and I find that it covers my living room and dining room really well. The filter is replaceable and has a 6 month life roughly. With all the allergies in my home, this air purifier has really helped keep everyone in a better state. I highly recommend this to everyone.