DSC-150 7.2 mp the 7+ mega pixel CCD would probably capture more detail than the 5mp cams, but that doesn't mean the image quality will be higher than that of a 5mp cam... image quality also depends on image processing algorithms as well as sensor quality. That said, the Sony CCD used in this cam is the same one used by Canon in the Powershot S70.
Power Shot A-95 offers the best selection of manual modes of the 3 camreas if control is what you're after.
Nikon Coolpix 5200 made to be a good point and shoot type camera, and from what I have read, does it very well.
Personally I love Canon and Nikon cameras, they just seem get things right.