This small interaction between me and Drago, about a racist thing Liam Neeson said a while back, made me wonder how what an actor says or does when he or she is not acting might put you off watching their films (or a director e.g. Roman Polanski and Woody Allen, or a singer with their music, etc).
Probably two slightly different themes I would say; celebritities you can't stand and equally as interesting, should the individual (and their personal life/deeds) be separated from their art i.e. Allen/Polanski as you highlight.
With regards the latter, I really don't know, I have struggled with this for a long time. If I am being honest would I never watch 'Chinatown' or view a Picasso again? The answer is no, so I guess that gives me my answer.
As for celebs:
Gregg Wallace - knobhead even before the revelations
Ricky Gervais - office is a masterpiece but he is a bully.
Russel Brand - hated him before the rape allegations but just confirmed what I suspected.
Jamie Oliver - insincere mockney nubbins that runs down restaurant chain after chain leaving massive debts to suppliers, and hundreds of staff out of jobs whilst he and his wife pay themselves millions in dividends. Why people treat him as some national treasure is a mystery.