ITT we post actually openings of weird/original/serious anime we wanted to see more of and post why.
No SoL/moeshit/harem/soft porn shit aka what makes the industry shit.
I'll start:
Plot continued in the manga
Pandora Hearts
https://www.youtube.com/watch?v=0Y4taQosGFs
Surprised by how few people know this or just hated it because of the anime. If more people knew PH it would become the new NGE. Heck, NGE doesn't hold a candle.
Umineko No Naku Koro Ni
https://www.youtube.com/watch?v=m7VLEBjM0cY
I'm torn between this and PH but Umineko has much more content because of the VN
World Trigger:
https://www.youtube.com/watch?v=zIT3HdkBK1k
Toei fucking sucks, but it's the only studio that could have made this show last the length it needed. Shounen, but has definitely more serious tones than one piece or fairy tale.

Original/complete:
C - The Money of Soul and Possibility Control
https://www.youtube.com/watch?v=W0p4syj-NMw
Imo my favorite MMORPG anime, short but doesn't cater to otaku with retarded loli love triangles/incest like SAO or LOGH.
UN-GO
https://www.youtube.com/watch?v=B8utsdwDi5U
Haven't finished this yet, the animation budget was quite low but it was entertaining
Yumekui Merry (anime has an original ending, continued in manga).
Been reading the manga back when I was in HS and I remember it was quite cool, reminded me of Fate, but less bullshit and more shounen battles. The author used to draw 2hu doujins before this.
https://www.youtube.com/watch?v=x0SUtZF7Uo4
91 Days
https://www.youtube.com/watch?v=Czj0m3vZhBY&disable_polymer=1
Last anime I watched, no regrets, but could have been longer.
ERASED
https://www.youtube.com/watch?v=Y9G20wV0KHE
This show clearly demonstrates how retarded the anime community is. They hype up a show after watching 2 episodes and then shit on it because it wasn't a pretentious show. Personally, I enjoyed it, who the hell cares where his time travel powers come from? A story doesn't need to be incredibly deep to be well executed.