Reviving this a bit...
I've got two that stick out... both why I don't like to chase prospects
1) Rymer Liriano 2011 Bowman Chrome Refractor Autograph /500. Pulled him, and held onto it thinking he was going to be the next big thing in San Diego... At peak that card was $100 and selling for near that, and had offers I wish I had taken... now, it's a dollar bin card and I ended up flipping it to Jsneeze50 in a large trade for pennies.
2) Another Rookie, Matt LaPorta... 2008 Bowman Chrome Blue Refractor Auto... If you don't know Matt, it's probably because you didn't collect in 2008. If you did, you'll likely remember the trade in 2009 that sent him to Cleveland for C.C. from Milwaukee. He was the Hype Prospect everyone had to have besides Moustakas in 2008. LaPorta's limelight shined and as quickly as he shined, he flamed out even quicker in Cleveland. One of my worst trades to remember, as I dealt a few HOF Autographs for it... And now, it's sitting in a box in my closest as a reminder to why I don't prospect non-Oriole players. lol
https://en.wikipedia.org/wiki/Matt_LaPorta
--- and then I just found out he finished his career in Baltimore... yikes! no wonder why I wanted it... bahahaha