Lucas Giolito, Nationals
Giolito had the stuff to be a top-5 pick in the 2012 draft, but arm troubles scared off plenty of teams before the Nats took a chance on him with their 16th pick and signed him to a near-$3 million deal. Tommy John surgery cost him most of 2013, so he's only pitched in just 11 games. Still, they were 11 very impressive games. The righty may have the best stuff in the minors, but he won't be making the show for a few seasons. Take a look at his near-100 mph fastball while you can.