I have Nikon, my mother bought a Canon, and a friend just got a Minolta. All in all, I prefer the Nikon. The cameras are great ergonomically for me and the controls are logically laid out.
The Canon is OK but I have to take a few minutes to re-learn the camera every time I use it. The controls are fine once I get used to them but they don't make as much sense to me as the Nikon controls do.
The Minolta controls are clearly laid out but are an ergonomic problem for me. I guess my hands are just the wrong size or aren't as flexible as they should be.