I don't remember Kane or Johnson, so I'll exclude them.
1) Crosby
2) McDavid -- People were saying he had GOAT potential
3) Dahlin -- People were calling him the best defenseman to ever be available in an entry draft
4) Stamkos -- Widely thought of as a special talent
5) Tavares -- Widely thought of as a special talent, but I remember people saying he wasn't as good as Stamkos
6) Matthews -- Considered a true franchise lock with a rare combo of tools
7) Hall -- Just considered to be a really good winger
8) MacKinnon -- Considered to be franchise changing, but wasn't considered as good as Jones
9) Ekblad -- Was projected to be a 1D but not necessarily elite
10) Yakupov -- Was considered to be a dynamic, sniping winger but with a lot of problems to work out
11) Hughes -- Was considered to be a really good forward, but there were A LOT of questions about him
12) LaFreniere -- He had a major fall from grace. When he entered the Q, people were calling him generational
13) Nugent-Hopkins -- Projected as a 1C who probably was going to need another year in major juniors
14) Hischier -- His ceiling was seen as a 1bC in the NHL