Vortex Humidifier.

This unit is made in the USA, easy to clean, easy to fill, and has run non-stop for 2 (5-month long) winters. The disposable wicks last a long time and contain most of the mineral residue, keeping buildup minimized even with super-hard water. The water tanks are designed without lids so filling is fast and easy, making the fan the only moving part.

This Vornado has all these. The fan is indeed very quiet at low speed - the most quiet of any other type (I checked about 6 or 7 others, including models from Bionaire, Holmes, Honeywell, Kenmore and some other less-well-known brands). So far the humidistat seems to work - turns the unit on and off periodically.