I'm not sure if this has already been a topic or not, but I think it would make for an interesting show: Things With The Worst Fans. As a special subcategory, or maybe just to weed out all the obvious answers, What Is The Best Thing With The Worst Fans?
Anything could be on the table - bands, TV shows, films, books, sports teams - and the latter version of the question could get into things that you might otherwise like but are put off by other fans, or things you do like but are kind of embarrassed to be associated with the fanbase.