Silicon is cheap (as little as $1 or less per Gbyte for moderately fast media).
So I've always subscribed to the idea of capturing as much image quality as possible. RAW gives you the most options, but if you don't want to deal with post-capture processing, then properly exposed JPEG files at the highest quality is the way to go. There will be increasingly noticeable differences at higher compression ratios, and these will show up as "blocking" of colors when you look at your image at higher zoom ratios, or loss of edge contrast. These artifacts, which depend on the complexity of the images may (or may not) result in a loss of fine detail in images which you may wish you had saved. You can verify the amount of loss for yourself by collecting duplicate shots at various JPEG compression ratios. For 4x6" prints, or viewing at low resolution on a computer monitor (such as on a web page), these compression artifacts will be of little consequence even at JPEG BASIC (16:1), but may become apparent if images are destined for viewing in a larger format.
But silicon (or magnetic media) is cheap. So why sweat it? Save RAW and/or fine JPEG and no worries about what the camera did to your image.