4. Roy Keane
When you watch Roy Keane on television getting annoyed with Adrian Chiles and his unfunny jokes about how bad the match is, you probably think he wants to hurt the presenter.
'Keano' is a legend at Manchester United, even though he once described the Old Trafford faithful as prawn sandwich eaters for their lack of enthusiasm. The midfielder abandoned the Republic of Ireland squad at the 2002 World Cup after the facilities were not up to his standards - a decision you can't imagine manager Mick McCarthy disputed too much.
'That' tackle on Alf-Inge Haaland in the Manchester derby was revenge for a challenge the Norwegian had put on Keane during a match in a previous season when the tall, blond midfielder was playing for Leeds United. If you read Keane's comments in his autobiography about the incident, they will explain his underlying ambition to get revenge on Haaland.
The Irish midfielder had great on and off-field battles with Patrick Vieira which so regularly came close to violence.