I just bought this one a few days ago. Cheap and simple, been using it every day. It works great! I only wish I had bought one sooner!
It has 5 stackable trays. If you need more room between trays you can take one or two of the trays and cut out the mesh part, leaving just the outer ring that will now act as a spacer between the other trays.
I have that one. I like it because it is passive and won't blow dust on my paint and I don't like it because it has no temperature control or even an on/off switch. It doesn't even have a power indicator light. I had to plug it into a power strip with one to know if it was on or not. Did I say I liker it? I do.