I think you're asking the wrong question, since your URIs should reflect the information hierarchy of your site, and ideally be easy for users to remember and type in.

So, if 'this-page' fits within the 'example' category then the first URI may be better. If the page is in the very top level category of your site (as 'about' pages and suchlike often are) then the second URI would be better.

I'd also suggest dropping the file extensions (i.e. www.example.com/example/this-page), but I guess that's another debate ;)