Loyalty is a scarce commodity in football nowadays. Sulky Jermain Defoe has epitomised that trend with his hasty return to Tottenham less than a year after leaving White Hart Lane. The striker's transfer got us thinking of football's most notorious mercenaries. We've picked out nine, but you can add your suggestions by clicking here, and vote for the game's ultimate mercenary from our list.

Jermain Defoe

Defoe seems the best place to start as the most recent entry in our top ten. He arrived at Portsmouth last January professing his delight at joining the club and his passion to move them forward in the Premier League. But as soon as Harry Redknapp (more of him to come) jumped ship and switched to Tottenham, Defoe became itchy. Anger at being left on the bench against Arsenal merely exacerbated his frustration with new boss Tony Adams and so the rumour mill swung into motion. He made no secret of his desire to rejoin Redknapp, much to the anger of the Pompey fans.

Defoe also has previous at West Ham. Despite being brought through the youth team at Upton Park, he handed in a transfer request less than 24 hours after the club were relegated. He moved to Spurs and is still berated by Hammers fans with the words, "you're just a short Paul Ince".