#3 Petr Cech
Petr Cech signed for Chelsea from Rennes for £7 million becoming the most expensive keeper in Chelsea's history that time.
It took some time for Cech to get back to his best following the collision in 2005 with Stephan Hunt. It left the Czech international with a fractured skull. The doctors advised him to stay away from football, but he had other plans in mind.
The Czech keeper went on to become a legend for the Blues before making a switch to Arsenal.
Petr Cech went on to win 4 Premier League, 4 FA Cup, 3 League Cup, 2 Community Shield, 1 Champions League and 1 Europa League while playing for the Blues.
Some of his personal achievements are 4 Premier League Golden Glove, 2 Premier League PFA Team of The Year, 1 Chelsea Player of The Year.
His performance in the Champions League final against Bayern Munich is still rated highly by many fans. Cech might be playing for the Gunners now, but that doesn't stop him from returning back home once he hangs up his gloves.