I actually really liked Willem Dafoe as Norman Osbourne, the problem was Green Goblin looked . . . . not that great. A good costume and a little tweaking here and there, and Dafoe would have been the perfect Green Goblin.
If it were up to me, I'd have given Willem Dafoe the rubber mask from the comics, only it would be done like Batman's cowl where he still has his actual mouth exposed and just use face paint to make the rest of his face match the mask. I think Dafoe could have benefited from letting us see his actual verbalized taunts and that creepy, wicked smile, but let his crazy eyes hide behind those yellow eye holes. They kind of went too minimalist with the Dane Dehaan version of Harry's Goblin, though, not quite making him the monstrous Ultimate Comics version of the Osborns when they're in Goblin form, which was kind of pointless, really. We did get to see that one, though, in Into the Spider-Verse. So if we get to see a proper Green Goblin, I think my original idea for the Goblin's mask would be the best way to portray it rather than a completely fixed mask like the one from the Raimi movie.
BTW, anyone have any idea who's supposed to be playing Taskmaster in Black Widow yet? I think I read that back when they were planning on having him in that cancelled show Most Wanted, he was going to be played by Oded Fehr from the Mummy and Resident Evil movies.