Exactly - this has been discussed before, imgur are using the approach I like the best: if you enter the site by its canonical domain name (forum.domain.tld or www.domain.tld), the new user gets the category list and can get a grip what is happening there. Users of the site will click the logo to return from browsing stuff, and should get redirected to /latest instead of /categories. They can also add /latest to their browsers’ bookmarks.
And that’s why I created this tiny plugin: Redirect / for non-logged in users? - with that, you can configure where a logo click takes your site visitors.