Mac and Bozer
I know that supposedly MacGyver and Bozer were best friends growing up. At least, that's what we've been told.
But when the show first began and we met Bozer (with his crazy movie special effects and costumes, etc.) I certainly did NOT get the impression that they were anything more than roommates. In fact, it seemed to me that Mac sort of simply humored Bozer; he didn't seem to treat him like an actual friend. I was actually kind of surprised when we learn that they were childhood BFFs, because nothing I'd seen led me to have that impression. At all.