From manufacturers that specialize in one type of humidifier, such as Desert Spring, to those that try to grab a little of every market, such as Honeywell, there is a lot to choose from when it comes to buying a humidifier for your home.
While a trusted brand name is a good starting point, it's important to know that reliability can vary across product lines, and almost all humidifiers come with complaints of one sort or another.
With pretty much all tabletop or console humidifiers, complaints run the gamut, accusing units of making too much noise, leaking, requiring frequent cleaning, having reservoirs that are difficult to refill and not performing as well as promised. There are also pretty consistent complaints that humidistats don't work correctly and machines have a short lifespan. You'll almost always hear that users find filters too expensive and don't like that they have to be replaced more often than claimed. Be it a Holmes or an Air O Swiss (which has generally good reviews, aside from price), there are always users not satisfied with some aspects of their unit.
So, decide on the most important aspects and make compromises for the rest to get a unit you can live with. If you don't mind placing the humidifier in a central area on a drip tray, leaking won't be an issue. You might find a unit with such complaints that otherwise performs well. The same goes for humidistats - you may not worry about how it works if you already have a reliable hygrometer and don't mind manually controlling the unit.
There are a lot fewer brands to choose from when it comes to whole-home units, but the good thing is you'll be able to find a lot more information about them from licensed installers, who can recommend popular models and the best unit based on your preferences. Generally, whole home humidifiers come with fewer complaints than others, but different styles can mean varying performance, cost, and energy and water efficiency. Some companies thrive on a good reputation from years of being in the business, while newcomers bring innovative features and a potential for less waste.
How to choose
You might want a cheap humidifier to get you through cold winter nights or a long-lasting unit with low operating costs over time. User reviews, such as those found at Amazon and Epinions, give hints about the humidifier's capabilities and downfalls long into the future.