Mauer showed flashes of his potential in 2004 and '05, but '06 was when he emerged as a force on the national stage. The Twins' backstop heated up with the summer months, swelling his batting average to .392 by the end of June. He slowed down a bit as the months rolled on, but not by much -- and after hovering around .350 for much of the second half, he officially became the first (and only) catcher in AL history to win a batting title when a two-hit performance in the season finale helped him finish at .347, four points ahead of Derek Jeter.

Mauer went on to win batting titles in '08 and '09 as well, making him the only catcher in AL/NL history with three.