Here's Baseball America's top 100 prospect lists dating back to 1990. It's really worth looking through them, because they're really interesting, but 2008 is kind of sad if you're a Red Sox fan.
Now, granted, some of those Red Sox prospects have had pretty good careers, but it's pretty amusing in hindsight to see how these things play out. I'm sure you could do this with any number of top prospect lists from any given year, but this one caught my eye.
Bonus Bonus: Back In 2001, Miguel Cabrera was ranked 91st and was listed as shortstop - he was two spots above his
Miami Florida Marlins organizationmate, and Kane County Cougars teammate, Adrian Gonzalez. Red Sox third base prospect Tony Blanco was just ahead of both of them.