I dunno, there’s so many great NES games with interesting mechanics, and totally hold up today. Stuff like the OG Mega Man series, Bionic Commando, Castlevania (especially CV3), River City Ransom, Batman (Sunsoft version), Metal Storm, Double Dragon 2, Mighty Final Fight (IMO better than the original), Ninja Gaiden series, Contra, Tecmo Super Bowl, Shatterhand… list goes on.
There’s a lot of great games for the system if you can look past the graphics. And there are still games being made either for it, or as homages. Stuff like Micro Mages (actual NES game that’s also on Steam and it’s great), Blazing Chrome (inspired by Contra/Contra 3), and stuff like Legend Bowl and Retro Bowl (retro inspired American football games), and The Messenger, which was Ninja Gaiden and Metroidvania inspired.