Just echoing many of you in here, chapter 3 was the worst because my favorite character (Ibuki) was killed and Mikan's execution was underwhelming; I felt like it didn't do justice compared to the murders that she did.
My favorite chapter is chapter 5 because I was convinced that Komaeda committed a suicide, but him depending on his luck to make the traitor a killer was a genius move. I wasn't expecting that at all.
Also, does anyone else was surprised that Nanami is the traitor? I mean, I would never suspect her to be the traitor since she's equivalent to Kirigiri in DR.
I'm pretty oblivious to small hints like Nanami knowing about Monomi's diary, so chapter 5 trial was a huge surprise to me.
My favorite characters:
Ibuki, because her quirky personality is refreshing to me and she always lightens the mood in this depressing game.
Gundam, because of the way he talks and his sacrifice in chapter 4.
Nanami, because she's a gamer and she always helps Hinata even after her "death."
My least favorite characters:
Saionji, because she's an evil and annoying little brat.
Mikan, because she killed my favorite character. She was my second favorite until chapter 3.