Canon and Nikon are generally regarded the best, but I'm not a photographer so I'm not sure. I just stick with those 2 companies because from experience with Canons, they have taken some sweet pictures. The Canon "A" series takes better pictures than the Nikon consumer models like the CoolPix model with 5.0 MP. My Canon A60 with 2.0MP takes better pictures than my friend's Coolpix 5MP camera because the images appear less blurry, and take photos better in dark conditions. 😉
Don't know much about photography, but I do understand a bit about imaging (x-rays, mainly). The reason Megapixels (MP) doesn't necessarily result in better image quality, or even better resolution, is because after a certain point, the pixel size is so small that it's not the determining factor in resolution. You can make each pixel smaller by getting a 7 MP camera rather than 4 or 5 MP, but the resolution will be indistinguishable even on larger 8"x11" prints. I only print 4x6", or possibly 5x7". The type/brand of CCD used, camera motion, lighting, etc, will have a greater effect on image quality than MP.
A high MP camera will still capture photos with poor resolution if your hand is shaky. The images will be a bit blurred, making it difficult for you to differentiate small things (ie: text on a piece of paper) as being separate, which is what resolution is, right? The CCD matters most, and Canon apparently uses good CCDs. 🙂