What I love about fighting games is the way you can see a person in how they play the game. When you play against someone you're seeing and reacting to their decisions on a split-second level. You get to appreciate sometimes their sneaky tricks.
There are so many little tics a person can show and reveal. How are they starting the round? Do they do a pre-emptive move, do they block, do they back away, do they dash up and do a move? How is this different from last time? Do they always start with airdash jC? What can I do about that to force them to get creative? When they get in, can they hold onto it? What if anything can I do to escape it? In the neutral, how are they countering my toolbox? When I whiff 6C in neutral, do they punish me for it? Do they respect my 2B? Maybe they don't hit-confirm and so they overcommit on combos? Maybe they risk it a lot in neutral and go for the 5Cs? Maybe they always get me low with that Pom 5A.
And then there are the sneaky tricks. I remember a time fighting a closely-matched friend in Them's Fightin' Herds. They were playing Pom and they did their dog super. They did this a lot in the set and, if I recall correctly, normally I would just block it. This time they did the super and then jumped over me, reversing my block direction. I was surprised, so I blocked the wrong way and ate the super. It was a delightful moment: Oooh, what a dirty trick.
There are so many little quirks that you can see and dirty tricks you can appreciate as they unfold. There's something neat about this when it happens that I love.