Volchkov immediately came to mind.
Sadly my team has some pretty epic ones dating as recently as 2001:
Igor Knyazev, 2001, 15th overall: played 2 seasons in the AHL never even coming close to the NHL or really coming close to anything resembling development. Returned to Russia, currently playing in the KHL. This guy is case in point as to why you don't draft a player simply because they had a strong tournament.
Jeff Heerema, 1998, 11th overall: played 34NHL games tallying 4 goals and 2 asists for 6 points. Was touted as an offensive winger or at worst a decent 3rd liner. Put up decent, though not spectacular, numbers in the OHL his draft year, although being that it was his rookie year in the O he was expected to keep improving. It never happened and he found himself as one of these AHL star/NHL bust types. Given the player taken immediately after him (Tanguay) and some of the others after that (Gagne, Regher, Kalinin, Jiri Fischer, Gomez, Cheechoo) the Heerema pick looks pretty horrid.
Nikos Tselios, 1997, 22nd overall: 2 career NHL games. It might be kindof unfair for me to have him listed here since he was considered more of a "boom or bust" type. Still, given some of the hype around the kid at the time I have to put him here. A lot of people figured his offensive game would translate to the pro level, but once he got to the AHL it was quickly figured out that he was relying on his physical gifts to put up points before rather then any actual hockey sense. He failed to develop at all and may have in fact regressed. I believe he's playing in somewhere like the UHL now.