Good Photography Camera?

I would consider myself to be past a beginner level photographer and I just want a better camera for more professional looking shots. It would be nice if it wasn't too expensive (under 400)? I'm looking for something more than the average digital camera. I currently have a Sony Cyber-Shot (12.1 mega pixels) and it takes great pictures and all, but I'm just looking for something more professional… I've seen some decent Canon's and Nikon's; I just don't know which ones would be the best for the kind of photography I'm looking to do. I want a camera good for taking shots of anything from landscapes, to portraits, to even sporting events.
Any recommendations?

The Canon G12 or Nikon P7100 lists for $499, maybe you can find a deal during the holidays or look at the last model which is just as good and $100 or more less.
http://www.dpreview.com/...on_cpp7100

GE x500, 16mp, 15x optical zoom, over 20 different settings, best part, $128 at walmart