Regarding this - I'd love a Zverev - Medvedev final. Their H2H is really interesting, when they were younger Zverev had no trouble with Medvedev at all. Recent games however all went the opposite side and a GS final might increase their rivalry a bit more as well - and we will need that once the Big 3 starts to retire.
Just watch games in the women's side, it's also very exciting, although I've lost the last time betting on the favourite, I should have listen to my gut feeling that this youngsters are going to take over this grand slam.
Of course, Zverev vs Medvedev will also be great, and just like on the women's side, it might signify that a new generations are taking over. Federer might likely retire next year and so is Nadal. Only one left is Dkojovic to keep the torch alive for the old generation.