Brandon Webb, 4 years, 19.5 Million dollars
This was signed prior to the 2006 season and covered the 07-10' seasons. This was a steal at the time for a pitcher that proved himself to be a solid innings-eater with some upside. When the 2006 season was over, that upside had been fully realized with Webb winning a CY Young Award. In 2007, he led the team to the NLCS before falling to the Rockies. The team nearly made the playoffs in 2008 as well. Unfortunately, on Opening Day, 2009, he suffered a shoulder injury that ended his career. He spent the 2009 and 2010 season rehabbing the injury, but just never was able to get healthy sadly.
However, his production in the 07-08' seasons along with getting them to the playoffs more than paid off this rather small contract. Webb finished as the CY Young Runner-Up and All-Star in both of those seasons. Brandon went 40-17, pitched in 68 games, threw a 3.15 ERA, 3.26 FIP, and 149ERA+ in 463 innings. Over those innings, he struck out 377 and produced 12.1 WAR. In addition to that, he had a 42 inning scoreless streak, which ranked 2nd-longest in MLB history at the time. Prior to the end of Opening Day 2009, he hadn't missed a start for 6 years.
Overall, this deal still was a steal. Two years of elite CY Young production for 19 million is cheaper than even half a season of elite CY Young production in today's time.