"I haven't given this much thought, but here's a preliminary list:
1) Bud Adams - Runined the relationship that his team had with the city through constant negotiation fumblings including Earl Campbell, Bum Phillips, Warren Moon, Jacksonville and finally Tennessee. A fanbase that once chanted LUV YA BLUE has 5 people show up at a rally to have the team stay. Played as the Tennessee Oilers, which made no sense, just to make sure that when Houston got a team again that they couldn't take the name (later negotiated its retirement).
2) Mark Cuban - Props for building up a dieing franchise, but is more recognizable than his players, constantly does something to get attention, dresses horribly, and let's not forget the worst TV show of all time: The Benefactor.
3) Jerry Jones - As arrogant as they come. Ran off a football coach after he had won consecutive championships. Coddled dope smoking, coke snorting players instead of keeping the only source of discipline around. Allegedly "dieted" his way into a new look, just like Michael Jackson. Similar attitude t Cuban, but ranks behind him due to championships.
4) Tom Hicks - did get bailed out by the Yanks, but first signed a REEDICKULUS deal with Alex Rodriguez handicapping his team for several years. Also, pays certain college athletes to 'play baseball' for him despite their talents in other sports.
5) John McCullen (former Astros owner before Drayton, I think I have the name wrong) - refused to resign Nolyn Ryan because of the difference of a couple of bucks. Told fans that Jim Clancy would replace him. Never listened to his GM's.
Add your own list and feel free to disagree with mine. "