I don't fancy any of those listed so far, but I had a very soft spot for James Belushi's brother - John. I found him tres amusing (Blues Brothers, Animal House, etc) but he also seemed to have an air of vulnerability about him.
O dear, it seems that my Achilles heel may be a man with a razor sharp sense of humour who needs his ego boosting.
Otherwise, I can't see myself clinging doe-eyed to the arm of a guy I found unattractive just because he was famous - although I might make an exception if he was rich as Croesus 