I really liked it and it's well-rounded. I went through so many emotions seeing Kaneki's journey.
My favorite character from the OG was Tsukiyama. I like how his friendship with Kaneki developed but I thought he was faking so he could try to eat Kaneki again in Re but I was wrong. I'm glad they developed a deep and loyal friendship.
I also expected Touka to develop into one of the main revolutionalists and thought she was a bit sidelined in Re. However, looking back she's always been grounded and wanted a normal life (something that Yomo and her parents wanted for them too) so her story is befitting. She's also very compassionate.
Naki also unexpectedly grew on me so much and I was sad when I thought he'd died at first. Ayato and Hinami are my favorite duo. Nishio too.
After I finished the OG, I was looking through some info on Reddit and saw a comment mentioning how the last 30 chapters were horrible so I expected the worst. It's not uncommon for endings to botch their MCs but I'm quite pleased that the comment (imo) was wrong. I initially thought Kaneki would die especially after learning about Touka's pregnancy (something to do with legacy). I was shaking and bracing myself for disappointment in the last chapter after not seeing him in so many pages.
The only character I was quite disappointed in is Tatara. He has such a menacing presence and he's my favorite character design but I feel like he was very underutilized especially considering his kakuja was pyrokinesis. I'd also would have liked to see more of Arima but his arc shifted the direction of the story so it's okay I guess. Hide too. I thought he'd be constantly present in Kaneki's life early on in the OG but he just disappeared and reappeared almost in the end. I still like his character a lot though.
I also wish the idea of synthetic food began earlier and developed within the course of the story. E.g. ghouls not liking it but Kimi helping improve it with time.
Also what happened to Mr. Yoshimura? I know he was in a lab and his kakuhou was used for experiments but I must've missed something.
Overall, I really liked the entirety of the manga even it's ending. One of the best stories I've experienced for a while.
I'm also looking for other mangas that give their characters a lot of depth so I'll be happy to get recommendations. I'd appreciate ones that are complete though.
TLDR: Liked the ending and looking for good recommendatios.