He is also the only driver EVER to be excluded from the Drivers World Championship.
In my 20+ years in the sport as a marshal he was one driver I always looked out for as he didn't slow for yellows as required. In fact he broke his leg and lost a possible championship because he ignored a RED flag stopping a race. He had passed two reds before he went off. That is fact and those facts were reported in the reports of that incident sent to race control. That red flag infringement alone, in my opinion, excludes Schumacher from being the best of his era as the red flag rule is a basic in all circuit racing ie cease racing, slow down and return to either the pits or startline as directed by the marshals.
To be the best of his era in motorsport, in my opinion based on 20+ years trackside, a driver has to have raced on road courses and ovals. Schumacher has never done that. Can you compare Schumacher with Jeff Gordon or come to that the late Gerry Marshal? Both drivers have raced in the same era as Schumacher. Gordon has just won his 77th Nextel Cup race and Gerry Marshal won over 500 races in career before he died during testing a couple of years ago. You can't and you can't say one is or was better than the other because they didn't race together. It takes more than race wins and championships to be a great driver. It also takes credabilty, which Schumacher lost when he was excluded in 97 and what he did in Monaco last year, and a good off track image. I have met both Schumacher and Gordon when they have been off track and away from the media and Gordon has the best off track image by far. Stats don't tell the whole story of a great a driver is. It is a pity that F1 teams don't allow their drivers to take part in IROC (F1 drivers are invited to take part in the series) then we would see who is the best