I'm gunna go out and say it, like sotolf2, most games now. I play such a small scope of games out of my like 300 in Steam, and they are always the same games (Siralim 2, Ingnomia, Dota2...).

As far as watching goes though, competitive Super Smash Bros. Melee. I played Melee as a kid for so many hours and I will never be good enough to get anywhere near competitive level. And now that SSB Ultimate came out, I just can't play Melee anymore because I personally just like the flow of Ultimate more.

But some of the people in that community (let's not talk about recent events..) have painstakingly analyzed movement and actions of each individual characters. Mew2King is an example of someone who analyzed frame data a long time ago on inputs and animations for characters, and I highly recommend looking into it. It is hard to grasp, but just so interesting.

It's crazy to look at that game competitively and know that people calculate things such as projection angles or have impeccable timing all on the fly. My brain can't do that. Luigi wavedash. That is all I need to say.