Halladay has compiled 65.9 WAR according to Baseball-Reference, which exceeds the total of Hall-of-Fame pitchers Bob Feller, Juan Marichal, and Hal Newhouser. FanGraphs agrees with this total with an even higher number, 67.6 WAR, which is based on his career 3.39 FIP. It goes to show that both the traditional ERA and sabermetric FIP both agree he has been an exceptional pitcher over his career.
Halladay's 2012 wasn't wonderful, but even then he was still worth 2.5 WAR according to FanGraphs. His 2013 was pretty disastrous, however, compiling a -0.8 WAR. As it turned out, Halladay threw his last Major League pitch in 2013. The Steamer projection systems still saw Halladay being able to pitch 25 starts at a 3.8 FIP (3.9 ERA) level, compiling about 2.2 WAR. In early 2014, however, he decided to hang them up, signing a one-day contract with the Blue Jays to officially retire with Toronto. In any case, he's definitely Hall-of-Fame material.
Thanks for the memories, Roy.
Photo credit: Wikimedia Commons