Proportions are important. Also there is nothing more off-putting than being in the gym and seeing a good face, a nice upper body.... and chicken legs. Also above parallel squats get your man-card revoked in my eyes.
I like for guys to have some bulk (and to be larger, and definitely stronger than me), but bf% is not that important, I find slightly fatter rugby types and really lean guys (like the ones posted above, though I probably like their look way more natural, without the extreme photoshop/lightning, dehydration etc.) equally attractive.
I guess an important aspect of it all is their attitude to fitness&health. If they're athletic, and train mainly for performance and health (whether for specific sports or just general) with some allowance for aesthetic goals (gotta do your curls), I find that way more attractive than just training for huge guns or low bf% to impress other people.
Or (I'm guessing this might be the same for a lot of other people), being strong and athletic enhances your attractiveness; as in if I've got two equally attractive guys, but one of them can c&j twice his bw, than I know who I'll ask to help poor old me with my olympic lifting technique.
But if I find someone unattractive (whether it be body or face), no amount of kg on the bar will change that. Cold, but true.
(woah, essay)