What kind of digital slr camera is the BEST but not so expensive?

Firstly, this depends on your standard of 'best' and 'expensive'. If you're a professional photographer, you'll want cameras on the top of the range, which aren't cheap - at all. If you take Photography as a serious hobby - like I - you'll want something like the Nikon D7100, Cannon EOS 70D etc. As for people who just use photography to pass time, then I recommend the Nikon D3100, Nikon D3200 or Canon EOS 100D.