My tablet is an Adesso CyberTablet 12000 and I've been using it for 6 or 7 years now, and it works great even after all this time.
As for software, I use it with Blender, Gimp, and Photoshop… With Photoshop CS2 being my primary, and Gimp as my secondary for 2D drawings.
Blender comes into use for both 2D and 3D, which gets a lot of use from my tablet, especially for painting 3D models.
Also…
I've been looking at photoshop cs6 but the heavy pricetag is shooing me away x.x
In addition to Gimp which you mentioned already using, there's also
MyPaint, and
Krita, as they also carry the very affordable price of free.