easy, the SD700.
Less megapixels=larger photosites=more light hitting each one=less noise=sharper and cleaner images.
Anyone who tells you otherwise is wrong. The other cameras
might have less noise in the images, but that's because of more aggressive noise reduction that smears details. You're probably going to print no larger than 4x6 anyway, if you even print them at all. 8x10 is the largest you should print these if you're shooting at ISO 400 because that's where the images REALLY start falling apart from seeing the noise, noise reduction, and all the other crap P&S's do to rape the image quality. at ISO 80, you
might be able to get away with a 12x18.