I know the list is long and growing. Flaunting their anal sex and not caring about their sin is the hallmark of so many homers. Each reader will have his/her choice for most despicable. Mine goes to those who glorified the sin of homer sex and became wealthy doing it. These homers spread the sin and make money, or made money, doing it.
My choice of the most despicable is the pair, Sigfried and Roy. They were Las Vegas showmen doing a magic and big cat show. Their show was the most popular on the strip. Strutting around in tight pants, deceiving the audience with magic tricks and presenting God's wild creatures as sex symbols was over-the-top sin. To make matters worse, they had $20 million when they died a few years ago.
Catholics may say, "May God have mercy." I say good riddance.
Siegfried & Roy - Wikipedia