That's a good one! I use children's animated movies as comfort watches a lot.

Middle-grade fantasy specifically can be really cozy, too. Or fantasy that feels aimed at that kind of age. Like Howl's Moving Castle (different from the Miyazaki movie), The Hero and the Sword / The Blue Sword by Robin McKinley (can't remember which book was first), the Young Wizards series by Diane Duane. Granted, some of these I haven't re-read in a looooong time, so they may not hold up quite so well as I remember, I dunno.

I also really feel this way about R.A. Salvator's Drizzt books. They're kinda racially problematic in retrospect, but in a way I can look past, and apparently Salvator has been making active efforts to mitigate that in his most recent books, and I really, really appreciate when an author is willing to listen and make changes based on that kind of feedback instead of just taking offense and kneejerk rejecting it, especially when he's been writing for so ridiculously long now. Anyway, the Drizzt books are very much light popcorn type reads, but they're a very specific flavor of popcorn read that I just haven't found replicated quite the same anywhere else. Something about Salvator's writing style, and Drizzt's melancholy journal entries, or something. Probably partly because of the hurt/comfort element, in that Drizzt has a shit time but always makes it through and also finds Found Family^tm, which is definitely a popular kind of theme today too.