Which backlink will be more useful?

[ATCnik]

Which bacllink will be most useful and gives me most juice? -link from all pages on the website (in footer), such as menu
-link from all pages on the website (in footer, display:none;), such as menu
-link from home page (footer)
-link from the page which have highest PR (PA) (footer)
-contextual-link from most relevant page on the site

[Paessler]

I would definitely go for the contextual link from the most relevant page (I assume that this is a high quality page, and that it is reasonably well linked within the website). I believe not only that google will put more weight on a link like this, but it will also send you targeted visitors which should be easier to convert.