I don't there this is a clear, definitive winner between Canon and Nikon. Not that long ago, Canon had an edge with speed, but with the D3 and D300, Nikon is pretty quick now too. And, Canon has that 21 megapixel dSLR, so if you're going for resolution, Canon is the clear winner. Overall though, to get a winner, you'd have to go specific body vs. body. XTi versus D80, 40D versus D300, you get the idea.