i'll go by 1st round picks who underachieved up until now, starting at 1999, cause you have to factor some development time into the equation
1999 - Patrick Stefan, Pavel Brendl, Brian Finley
1998 - Manny Malhotra, Rico Fata
1997 - Dan Tzachuk, JF Damphousse, Matt Zultek, Dan Cleary
1996 - Boyd Deveraux, Dan Focht
1995 - chad kilger, aki berg
1994 - Jason Boterill, Chris Dingman, Brett Lindros, Eric Fichaud, Jamie Storr, Jason Bonsignor
1993 - Alexandre Daigle, Todd Harvey
some guys i see becoming disappointments, or at least not living up to expectations
2000 - Jeff Taeffe, Krys Kolanos, Raffi Torres
2001 - Alexander Svitov, Carlo Colaiacovo, RJ Umberger, Jason Bacashihua
2002 - Jakob Koreis, Dan Paille, Martin Vagner, Scott Upshall
2003 - Braydon Coburn, Steve Bernier, Marc-Antoine Pouliot
2004 - Evgeny Malkin, Andrew Ladd, Al Montoya, Alexandre Picard, Rob Schremp
ok let me have it