For years on this site, the Rule 5 draft has been a huge point of interest. There are a few reasons for this.
The biggest reason was that in 2003, the Pittsburgh Pirates lost five players in the first six picks. Those players: Chris Shelton (to the Tigers), Rich Thompson (to the Padres), Frank Brooks (to the Mets), Jeff Bennett (to the Brewers), and Jose Bautista (to the Orioles).
One of those names definitely stands out. The Pirates had to re-acquire Bautista by the end of the year as a Rule 5 pick from their own system in order to retain him.