How many megapixels?

[Myka]

I need to buy a new camera (the G9 didn't like the swim in the reef). Considering all my cameras seem to meet their untimely demise in approximately 2-3 years, cost is a concern. I don't see the need to buy a 25 MP camera if I don't need one. The only reason I blow photos up is just to frame them and put them on my wall for a year or two. I will be buying another Canon camera.

So, simple question. If I never blow a picture up bigger than 16x20" (which is a rare occurrence anyway) and usually 8x10" is the biggest, what megapixels range should I be looking in?