Re-designing main menu structure on a magazine site

We've got a well-established Wordpress magazine-type site with over 3000 posts and quite a lot of categories (100) and tags (117). These categories are needed as we write about quite a diverse subject, but I've been having a look at our current menu setup (megaMenu type affair with a lot of links) and I was wondering whether it's worth moving to a simpler/more streamlined main navigation and showing the sub menu items in a different way. The reason I say this is most cats/tags are used in the main menu which is a lot, and that's before any on page links are taken into consideration.


I've also been looking at the analytics and seeing what the most popular cats/tags are - Do we want to concentrate on those only, or from a usability perspective should we give users as many options to find what they may be looking for instead?


Would appreciate some help to get my head round this