I've watched & read both and I think Dune comes on top on both ends. It is not without flaws, but it is close to a masterpiece. Movie version is really good and the lack of humour or easygoingness is intantional, the book is the same and the movie simply follows it faithfully. Plus sound & music design are Oscar level.

As for Foundation, I expected a lot more; appart from amazing visuals, is just terrible. Even great actors can't save fundamentally flawed script and porly written source material (I have a review published).