Pitch type: My pick, eyeball average between FanGraphs pick by "pitch value runs above average" and Baseball Analysts "run value per 100 pitches". (These are very similar metrics, so there isn't much of a difference.)
Fastball: Verlander, Haren (this guy is top 3 in a few pitches. though he doesn't throw 100 like Verlander, apparently Haren somehow has more "rise" on his 4-seam FB's than any other pitcher and no one comes close to his 4-seamer as far as effectiveness goes)
Curveball: Wainwright, Wainwright/Wandy (Wandy has had one of the best curveballs the last 2 years as well, including the best curve in 2007).
Slider: Greinke, Greinke/Dempster (not sure why Greinke doesn't throw it more often, like Dempster does. also important to note there that Marmol's slider has the most overall movement in the game, with a top 5 ranking in both vertical and horizontal movement. maybe this is why he can't get it over the plate anymore!)
Change: Lincecum, Lincecum (not even close. Santana's is still really good, but it doesn't play as well off his weakening fastball anymore)
Cutter: Rivera (he and Roy are both sick nasty, but it's Rivera's only pitch! would love to see how Roy would do if he only threw a cutter. would like to note here that this is probably the best pitch in the game, given that hitters know it's coming each and every time, and yet his career BAA is .212. silly stuff.), Halladay/Rivera (analysis shows that Rivera has more break away from RHB's, but Halladay gets more sink. would also like to note that Mr. Haren is 4th on the cutter list, giving him 3 legitimate "out" pitches with his FB, CT, and SF)
Sinker: Lowe (Webb, when healthy), Lowe (though one could make a case for Pineiro and his league-leading 61% GB)
Split: Harden (misses bats), Haren (induces groundballs)