Should I use f22 for sharp landscape prints?

If I want to get best sharpness from foreground to background in a landscape with 5d and 17-40 f4L, should I use f22, or will I get sharper results by using larger apertures such as f16 or even f11?

I am thinking in terms of printing photographs rather than web display - web display always looks much better, whereas prints tend to show up all the little flaws etc. I want to produce sharp landscape prints.

I would be interested to hear opinions on this, particularly as someone posted yesterday on a thread about 5D settings, that f8 was the optimum aperture as it matches the lens resolution limit to the sensor resolution limit - see here - http://forums.dpreview.com/forums/read.asp?forum=1032&message=26812103

Thanks for any help on this frustrating subject!