I use a Pentax k10D DSLR. I love it. It takes 10.1mp, it is weather sealed, and has a built in image stabilizer, so any lens you use will have image stabilization. Also, you can use just about any lens Pentax ever made, that is a K mount lens, and for their other mountings, you will need an adapter. Plus it won't break the bank either, and is fairly simple to use.
However, Pentax no longer makes the K10D, they upgraded to the K20D and a slightly lower intro model the K200d, and I think they have a K2000d as well. But you may still be able to find a K10d.
The only drawback, in my mind, is getting it serviced. Because it is not a Canon or Nikon, not every camera shop will be able to service it, or even have lenses readily available for it.