10 Gideon Electronic Plug-in Air Purifier #9 GermGuardian AC4100 3-in-1 Air Cleaning System #8 GermGuardian AC5250PT 3-in-1 Air Cleaning System #7 GermGuardian GG1000 Pluggable UV-C Sanitizer and Deodorizer #6 Holmes HEPA-Type Desktop Air Purifier #5 Hamilton Beach TrueAir Allergen-Reducing Ultra Quiet Air Cleaner Purifier #4 PureZone 3-in-1 True HEPA Air Purifier #3 Honeywell HFD-120-Q QuietClean Tower Air Purifier #2 O-Ion B-1000 Permanent Filter Ionic Air Purifier Pro #1 GermGuardian AC4825 3-in-1 Air Cleaning System with True HEPA Filter