Hard to say anyone but Yakupov is the biggest bust in recent memory. He was a 1st overall pick who was traded for a 2nd rounder after 4 years, and then was not qualified by the team that traded for him. It was a bad draft, and maybe he wouldn't have been a top 2 or 3 pick in most other drafts, but that is an absolutely terrible return for a top 5 pick. G. Reinhart was also bad, but at least Snow somehow salvaged that value by getting a 1st (regardless of what it turned into) and a 2nd before his value completely tanked.
I mean, how many top 5 picks were waiver fodder or unqualified UFA's before they were 24 in recent memory? I keep a loose list of players drafted in the first round in groups of 5 pick cohorts to see the rough value and return of each range. I've done this for every draft from 2005 until 2012 (will add 2013 at the end of the year), I don't go past that, as it takes some guys a bit to settle into roughly what they are. Here's how I've grouped the top 5 at the end of last season. Some guys placement you may disagree with, but I don't think I'm off by a tier with anyone. I would move G. Reinhart down to outright bust at this point and he would be the only guy in that category. Also, keep in mind, its hard to compare guys drafted in like 2005 who have pretty defined careers to 2012 guys. For example, Alzner is now an overpaid guy on the bottom pairing, but at his peak was a valuable top 4 shutdown guy. For 6-10 the only guys I currently have as outright busts are Hamil, Filatov, Glennie and McIlrath.
Superstar (7)
Sidney Crosby
Carey Price
Patrick Kane
Drew Doughty
Steven Stamkos
John Tavares
Victor Hedman
Star (7)
Backstrom
Toews
Kessel
Pietrangelo
Tyler Seguin
Taylor Hall
Ryan Johansen
Top Line/Top Pairing/Starter (7)
Bobby Ryan
Erik Johnson
JVR
Kyle Turris
Huberdeau
Duchene
Morgan Rielly
Top 4/Top 6/Fringe starter (11)
Jack Johnson
Jordan Staal
Brayden Schenn
Evander Kane
Nino Niedereiter
Ryan Nugent-Hopkins
Gabriel Landeskog
Adam Larsson
Ryan Murray
Alex Galychenyuk
Karl Alzner
3rd liner/5th D (5)
Benoit Pouliot
Thomas Hickey
Zach Bogosian
Erik Gudbranson
Ryan Strome
4th liner/6th D (3)
Luke Schenn
Nail Yakupov
Griffin Reinhart
Outright bust (0)