#1 Winston Bogarde
Winston Bogarde could top any list in world football for bad signings. He was signed by Gianluca Vialli in 2000. The Dutchman Winston arrived on a free transfer after not very successful spells at AC Milan and Barcelona and he soon became a huge monetary burden for the Blues because of his wages.
Bogarde joined Chelsea at 29 years of age and earned £40,000-a-week, which amounted to a huge £2m a season, and this was before Chelsea became extremely rich under the ownership of Abramovich.
But soon after Claudio Ranieri took charge of the Stamford Bridge he made it clear that Bogarde wasn't in his scheme.
Bogarde persisted though, insisting he would honour his contract at Stamford Bridge. His reason was that he wouldn't be proffered such a lucrative contract anywhere else. Chelsea attempted to force him out by relegating him to the youth and reserve sides but Bogarde devotedly turned up for training every day.
The 6'2 defender managed only four starts during his four-year stay at the Blues in which 11 of his 12 appearances came in his first season at Stamford Bridge and became a figure of ridicule for Premier League fans.
In 2005 he retired at an early age of 34 after failing to acquire a new deal with the club and also fairly failing to find a new club. He is quite surprisingly presently the assistant manager of Jong Ajax, the youth team of Ajax.