he's got this smolderingly hot thing going on without even trying or even being aware of it, and on top of all that he's mega talented, funny, smart, seemingly sweet and exudes this kind of innocence
YIS! You captured it perfectly, IMO. I'd add "with a touch of snark"
I was immediately drawn to Jemaine when first seeing the show too, and on the show, Bret often has such a silly or even vacant look on his face (I know it's intentional!), but then on some episode or other, I was struck by the fact that Bret is really, really very good-looking. It surprised me! LOL To be honest, if I were to simply bump into Bret on my daily commuter train (very likely I'm sure), I'd be just as thrilled as if it were Jemaine.
eta: This is now my favorite thread. I'm still a relatively new fan, still in the gushing and adoring phase.