in my limited experience with both brands of digital point and shoots (i have a lumix and my wife has a canon), my 5MP lumix dmc-tz1 takes a brilliant picture when there's a decent amount of light, but tends to get very noisy in low light conditions, the flash also seems a bit shallow. the color is usually spot on though.
her canon is only an older 3MP model, but almost always takes a respectable picture in a variety of lighting conditions.
your best bet would be to check out flickr - you can filter images by camera make/model, then you can see what other people have done with their cameras.