Ismail Gunduz, who plays for SK Rum in the Austrian 4th division, was shown a second yellow card late in a match against SPG Innsbruck West, at which point he reacted angrily to the decision and headbutted the referee. His club got rid of him immediately after the game and not the Tirol FA, who run the Austrian 4th division, have given him a 70 game ban. That's got to be the longest ban ever? (other than a life ban which I think a couple of amateur players have received from local FA's) He's appealing, claiming he slipped.
David(Bronco) Lane played for Sheffield Wed in 1st Div and was banned for life, subsequently reduced to 8 years, for match-fixing and went back to playing football. My sister dated him a couple of times before the banning.
P Peter Swan was also banned in the same scandal but returned to play briefly in the early seventies. I was at college in Chesterfield and my girlfriend was a Sheff Wed supporter so we went to Hillsborough to watch the game against City. I think it was Swan's first game back and we lost 4-2. Pearson scored two then got sent off for calling the linesman a "bloody onion."