I have a cheap wooden table from Ikea that is my humidifier table. It's several years old and I've gone through several humidifiers. While the table is warped, its more from spills than humid air - though I think any humidifier will tell you not to put it on wood.
Anyway, I currently have a Sunbeam one that I really like. I got it at Home Depot. I was looking at Target awhile ago and they seemed to have a really nice selection, too.
I use the website "the sweet home" for reviews, and I know they review some humidifiers, but the one they deemed the best was more than I was willing to spend.