"I'm really fascinated by speedrunners who can beat my favorite classic games less than an hour, sometimes in minutes. Some of that is cutting weird corners but often it's pure excellent execution."

Ocarina of Time speedrunning has gotten to a really weird place now, where they basically set the character's name to a string of bytes which are executable code, and then de-reference a pointer to it and warp directly to the end credits, all within a few minutes of gaining control of Link. But, the community has a whole bunch of categories for different types of runs, from ones that are basically the Any% category before SRM (stale reference manipulation), to semi-legitimately beating all the dungeons (though with lots of sequence-breaking), to fully glitchless. It's a lot of fun watching some of those other-category runs for a taste of "normal" gameplay done at a very high level.

Another thing that's fun to watch runs of is randomizers (chest contents, quest rewards, sometimes even doors), since then you're not just seeing high level play, you're also seeing someone doing the live work of reasoning about their route through familiar-but-scrambled territory:

https://ootrandomizer.com/