Who are the best players in your team's system who were left off the 40-man roster and are now eligible to be selected in the rule 5 draft?  I'll start with my team, the Tigers:

C James Skelton: An OBP machine with quick feet and solid defensive skills behind the plate.  I'm very disappointed the Tigers didn't protect him.  Teams with an opening at backup catcher would be wise to give him a look.

RHP Luis Marte: When he's healthy, he's got a low 90s fastball that he can bump into the mid 90s and a decent curveball.  However, he hurt is elbow midseason and was only throwing 88-91 mph when he came back.  He has also battled soreness in the Arizona Fall League.  He might be worth the gamble if he can say healthy.

RHP Jay Sborz: A former 2nd round pick who struggled mightily in his first few years in pro ball.  He figured it out this year however, and pitched very will out of the bullpen in High A.  He's got a mid 90s fastball.

Edit: It turns out that Marte is NOT rule 5 eligible yet.  My apologies.