Like him or hate him, Roy Keane was one of the toughest and hardest working players on the pitch in his 18 year football career. From his scrappy beginnings at the semi-pro Cobh Ramblers to stints with Nottingham Forest, 12 years with Manchester United, finishing up his career at Celtic, plus the turbulent years on the Ireland National team, Keane has both been a team leader and quite an outspoken player on and off the pitch. Respected, hated, and loved in football, Roy Keane is one of the true tough guys of the modern football era. One of my favorite incident being the Manchester United v. Arsenal tunnel incident with Patrick Viera, after Viera decided to pick on wee Gary Neville. Judge for yourself.