For me, it's Aaron Gordon and it's not really close. When you discuss "overrated" it has to be relative to expectations which were sky-high at times for this kid. It is a bit unfortunate that he won the dunk contest, that put him on the radar screen as some kind of amazing up-and-coming young player. The reality is that he's just a great athlete but without the associated basketball skills you might expect.
WCS is a close 2nd.
Brandon Ingram anybody? Again, think about expectations.