Fernando Alonso - Renault
Alonso may have cruised to his maiden title in 2005, but he was forced to fight every inch of the way during a tense second half in 2006. The pressure caused cracks to appear in Alonso's off-track facade but, on circuit, he was rock solid. Few drivers are able to wring the best out of the car with Alonso's consistency and ability to avoid race-ending mistakes.
He may have enjoyed a stroke of good fortune in Michael Schumacher's engine failure at Suzuka. But, considering that Alonso himself had lost 16 points to mechanical unreliability at Hungary and Monza, the scales evened out. If there were any doubts about Alonso's worthiness as a champion in 2005, the young Spaniard comprehensively dispelled them this season.
In what was ostensibly his last year in F1, Michael Schumacher went out on a relative high, demonstrating that he still has the beating of most rivals on most days. Mistakes at Australia, Monaco and Hungary cost him dearly. Against a lesser rival than Fernando Alonso, he may still have recovered from those mistakes to win the championship. But Alonso didn't give him a break all season.