I know Curt Schilling is 9-2 with a 2.23 ERA.
I wonder which pitcher (starting, not reliever like Mariano Rivera) has the best post-season record with an excellent ERA and at least 10 decisions.

John Smoltz is 15-4 with a 2.65 ERA and 194 K's

Orlando (El Duque) Hernandez is 9-3 with a 2.55 ERA and 107 K's

Orel Hershiser was 8-3 with a 2.59 ERA and 97 K's

Dave Stewart was 10-5 with a 2.84 ERA and 74 K's

Jim Palmer was 8-3 with a 2.61 ERA and 90 K's
.

Lefty Gomez was 6-0 in the World Series. If there is another with an equal or better record he got it with pitching in DS and LCS games. (And beyond Gomez, I don't know!)