Obligatory shoutout to !anime@ani.social if you want a more anime-focused discussion. Of what I have watched (or seen enough of to make a judgement) there are a couple standouts. Note that I haven't really watched much western animation in recent years.
- Frieren: Beyond Journey's End - !frieren@ani.social
- The Apothecary Diaries
- Heavenly Delusion
- Delicious in Dungeon - !dungeonmeshi@ani.social - This one is done by Studio Trigger, so it is a bit stylized, but I adore the animation in this series
- Jujutsu Kaisen - I haven't watched this, but I have only seen tremendous praise for season 2's animation (despite the studio's working conditions)
- Demon Slayer - another show I haven't watched, but have seen plenty of gorgeous clips
Wildcard answer would be Star Wars Visions. Each episode is done by a different animation studio, so it can be up to personal preference as to which ones you like, but there are some great showcases in the show.
Edit: If you care a lot about animation quality, I would recommend checking out the SakugaBlog. It goes into deep dives on Japanese animation. For example, they did a whole running series on Frieren (link to the first article).
Here is a guide to a third party extensions repo that was linked in a discussion thread the other day.
I haven't personally done this with my Tachiyomi yet, but have heard from others it has worked well.