Music, of course.
Also, I'm not sure how to word it but like, things that get the wheels turning in my brain (positively). Like while I'm reading a philosophy paper and trying to make sense of it, find faults or decide if the arguments make sense, I feel good while doing that, invested and interested. Maybe it's having some sort of thing to solve or strive to figure out, like a goal of sorts. Puzzles I've always liked too and when I can get into them also distract me pretty good, recently I solved "Eisenstein's riddle" or something like that, it was a good half hour spent.