/r/Strava and a bunch of the cycling ones like /r/Velo and /r/bikepacking, not very optimistic that there's much intersection between existing subsribers and those willing to leave Reddit for Lemmy but I can always live in hope!

Bropil and birl are honestly the ones I'll miss the most that are no NSFW or owned by a company

Probably the machine learning/AI ones like r/singularity and r/artificial.

R/daddit a big group of wholesome Bandit wannabes that I could really relate to.

At the moment, /r/horrorlit is one of the subs I browse the most and I haven't found a specific replacement for.

I'm going to miss r/hexandcounter. Wargaming is already a niche genre of boardgaming and the hex and counter is even further niche

Gonna miss the apex legends subreddit

r/screenunseen. Every few months Odeon (a big UK cinema chain) give hints to a movie and sell tickets without telling people what it is. Usually released a few days early or that won't get a wide release.

Became the sub for all things Odeon which is handy since I go so often.

r/CFB. There's one college football community here that I've found but it only has 3 people and no posts yet.

R/crt and r/crtgaming are the first that come to mind. Damn i love old tube tvs.

HighQualityGifs and their savagely, wonderful Gif Tournament

/r/skeptic

PSA: We're still in the early stages of Lemmy. Reddit was like this too when Digg first went down. If you don't find a community you liked - make it! And once you make it, post as often as you can in it.

r/croatia, r/askbalkans r/Balkans_irl and other communities with mostly people from balkan