Guess I'll have a look at 2018 this time since spring is so prominent. Last year I recall I went and checked every OP and ED in a couple of seasons so hopefully I haven't forgotten too much.
I might as well get one year in the correct chronological order though so starting off with winter. Three OPs in winter made the list, apparently, and the first one to go was one I can't say I care for. Granted, that's mainly because I actively don't like the song, so there's that. But also, to be perfectly fair, I was on the fence about a lot of winter openings, so while it wasn't exactly even close a favourite of mine, it wasn't exactly alone there. Anyway, stuff I liked. I didn't even attempt to watch the show itself, but I liked Death March to a Parallel World's OP song (Keiichi Hirokawa's been pretty great in the last few years). I was one of the few people that liked Hakumei to Mikochi's opening too, not that I expect that to make it with its visuals. The Junji Ito anime's opening was a low-key banger too. How To Keep A Mummy's opening was okay, but I felt the ending was a lot more memorable. The Antarctica anime's opening was pretty memorable. Oh, yes, and Yurucamp's existed I guess. I dunno if any of those would've been high enough for me to not snub myself though. Maybe Hakumei or Antarctica but I doubt it. Ones I *might* have though would have to be... Violet Evergarden's (though only borderline), Takunomi's (though I would've had it lower than other Rasmus Faber openings for sure), Ramen Daisuki Koizumi-san's and Mitsuboshi Colors....... And maybe the ep1 opening for Pop Team Epic. I liked the real one too, but again, probably not in. You might think with all the shows I listed, I actually liked the season, but honestly it just happened to have a lot of openings hovering around a mid-7/10 range to me, in addition to plenty below that. None of them would've hit top 50. More shows than not that I mentioned even had better EDs. So yeah, eh.
Spring, the big season. 7 openings on the list somehow. The three that surfaced thus far are all ones I overlooked to some degree. To be honest, this whole season was definitely the one I overlooked the most last year, but I suppose that's more on me more than anything. Still though, it was also a season with bizarre stuff like this: https://animethemes.moe/video/FumikiriJikan-OP1.webm. Besides that, I don't remember that much and probably would've struggled to get 7 myself lol. Ones that I do remember though include Alice or Alice, Amanchu Advance, Hisomaso, Gurazeni, lostorage conflated WIXOSS (which didn't hold a candle to the older stuff but was good on its own merits), the Soma opening that season, Tada-kun (though it's not Masayoshi Oishi's strongest offering in the last few years) and (I wish I didn't, but) Uma Musume. I guess I could've picked five of those, at least. Probably only 3 though.
Summer! A good summer season. I was one of the weirdos that liked Asobi Asobase's opening a lot and never got tired of its swerve tactics. That would've likely made top 50 for me. Gokudols opening cracked me up, and even more with the special version. I can't believe they got Masayoshi Oishi to make a parody of the Kemono Friends opening, after all the yakuza money laundering scheme jokes surrounding kf itself. Visually I liked Chio-chan's opening, though the song got stale. Probably a close snub. I hated Grand Blue, but its opening was strong. Hanebado's was good too. Harukana Receive was excellent. Cells At Work was strong and deserves bonus points for also having a great english version too. Holmes of Kyoto's was strong in the visuals department. Ongaku Shoujo/Music Girls likewise stood out a lot more than I expected. VORACITY (in Overlord III) was the biggest banger in any anime in recent memory, and Tom H@ck also had another treat that season with Yama no Susume S3's opening. What a strong season. I'd say of those, I'd have likely included around... 6-8 of those? Good stuff.
Lastly fall. Compared to summer, a season I would consider good, but not great. Also a season I missed a lot of since it was one that I focused on watching stuff with a friend instead. It had Adabana Necromancy, an opening with inconsistency that mirrored the show. It feels almost like sacrilege for it to not make it, but its underwhelming ending hurts. It had yagakimi, with an opening and ending that I never managed to remember despite their quality. It had Tiramisu, surprisingly having one of the more memorable openings despite being 30 seconds long. It had Gridman, which... Had a surprisingly normal song in retrospect, which my friend liked a lot. I guess I can't judge that as a fault though given how much I likewise defended Merc Storia's opening. What can I say, Mili had good stuff then. Overall, the one that stuck with me the most though was (De-De-De-De-De) Devidol's. It's a real shame it went unsubbed past ep1. I think honestly I would've only had 3 at best from it.