It's got to be 1984, and to be honest I don't think that's even debatable.
You have:
* Michael Jordan (Best SG of all time, arguably best player of all time)
* Olajuwon (Top 5 center of all time, along with Kareem / Wilt / Russel / Shaq)
* Barkley (Top 3 Power Forward of all time, along with Duncan / Malone)
* Stockton (Top 2 Point Guard of all time, along with Magic)
I mean seriously, that's four guys in this draft class who rank top 5 (or better) All-Time at their position.
By comparison:
- 1956: 2 guys who are top 5 all-time at their position (Baylor, Russell)
- 1996: 1-2 guys who are top 5 All-Time at their position (Kobe, maybe Iverson)
- 2003: 1-2 guys who are top 5 All-Time at their position (Lebron, maybe Wade)
Really no debate there.
Other's worth mentioning:
-1985 (Karl Malone, Patrick Ewing, Joe Dumars, Chris Mullin)
-1987 (David Robinson, Scottie Pippen, Reggie Miller)
-2008 (Russell Westbrook, Kevin Love, Derrick Rose)
-2009 (Steph Curry, James Harden, Blake Griffin, Demar Derozan)
-2010 (Demarcus Cousins, John Wall, Paul George, Gordon Hayward)
-2011 (Kyrie Irving, Kawhi Leonard, Klay Thompson, Jimmy Butler, Isaiah Thomas)
-2012 (Anthony Davis, Damian Lillard, Bradley Beal, Andre Drummond, Draymond Green)
Man, looking at some of those lists it just makes it stand out just how bad the most recent drafts have been. I would consider every guy I've listed above to be either superstars, or guys with superstar potential. 2015 has easily been the deepest of the past 5 years, and I still can't see more then or 2-3 guys in that draft class who I feel have legit Superstar potential (Towns, Porzingis, maybe Booker at a stretch). The other years have been significantly worse then that.
Has to leave me wondering how much this drop of in draft depth has to do with the push for guys to leave and enter the draft at 18-19 year old freshman, versus the older days when most guys would stay in college for 2-3 years and come draft time we usually had a handful of clear stars.