Another Celtic hero who almost joined Rangers first. Back in 2000, having embarked on a fantastic scoring run for Wimbledon, the former Arsenal man was linked with a move north of the border. The two clubs agreed a fee and Hartson agreed to a contract, but then issues were brought up in the medical and the medics said he wasn't worth the risk. Naturally, Hartson was disappointed but suggested he'd get his head down and prove that assessment wrong, which he ultimately did after signing for Celtic and scoring 89 league goals in 146 games. Which must have been somewhat shocking for those at Rangers who had insisted he wouldn't make it through his contract without some serious injuries.