The Rockies had the 25th overall pick in 2008 after getting to the World Series in 2007 and they decided to draft left-hander Christian Friedrich with that. He has a 10-28 record in parts of 4 seasons in the majors, 3 of which were with the Rockies, with a 5.37 ERA.
The draft ended up being one that was not that great as only three players from the first round have a career WAR of 15.0 or higher. They are Buster Posey (39.8 WAR), Eric Hosmer (15.6 WAR), and Brett Lawrie (15.1 WAR).
There are three notable MLB players who followed Friedrich in the first round.
Gerrit Cole: 28th overall pick, one time All Star, came in 4th in the NL Cy Young Award voting in 2015 as well as ranking in NL MVP voting in 2015
Lance Lynn: 2012 National League All Star
And, of course, the Rockies GOAT Jordan Lyles (sorry, I had to)
There were a lot of successful MLB players that came in the later rounds of the draft including current Rockies Charlie Blackmon and Bryan Shaw, Brad Hand, Tyson Ross, former Rockie Tyler Chatwood, Craig Kimbrel, Brandon Crawford, Dee Gordon, Jason Kipnis, Josh Harrison, Kolten Wong, current Rockie Chris Rusin, and George Springer.