Oh perfect timing, I was just going to ask you guys who your top 3 favorite characters were, and why
Celeste
+ Morally bankrupt schemer who sees her former classmates as little more than expendable chips / pieces to be manipulated as she sees fit.
+ Elusive history and personality, adding to her mystique as a character. Even having finished the game I'm still not entirely sure how much of what she said about her past was genuine.
+ One of the few to successfully commit premeditated murder. The most villainous character outside of Junko and (arguably) Mukuro.
+ Her performance during the chapter 3 trial was one of the game's highlights for me. Watching her facade crack, hurriedly repair itself and then gradually shatter into pieces was enthralling and partially compensated for the fact that I was effectively killing her.
+ Favourite design / appearance from the game, with or without her drills. Gothic lolita is the pinnacle of fashion.
Toko / Jill
+ Jill is manic hilarity incarnate. Her mannerisms, dialogue and actions were absolutely among my favourite of the cast.
+ Toko herself was high tier as well, largely for the humour she generated with her gloomy, introverted demeanour and fanatical devotion to Togami. Actually, the dual personalities combined were responsible for a large proportion of my laughs in the second half of the game, at least until the mastermind revealed herself.
+ One of my favourite designs, making her a worthy cover star for Book Girl and the Repressed Psychopath.
+ As an aside, I heartily approve of Jill's murderous methods. She looked sublime whenever she was posing with her trademark scissors.
Chihiro
+ Displayed admirable bravery in facing up to his inner weakness, in spite of his meek personality and the horrific circumstances the cast found themselves in.
+ Further respect due for helping his former classmates even in death through Alter Ego, culminating in his crucial protection of Makoto during the chapter 5 execution.
+ More adorable than a jute bag full of kittens.
+ General computer nerdiness. I suspect Nanami from the sequel will be popular with me for similar reasons.
Junko deserves an Honourable Mention for being a strong contender for the 'Most Batshit Fictional Character' I've ever had the pleasure of encountering. Bearing (dohoho) in mind her role as Monokuma, she was an excellent villain. I want to give Sayaka an HM as well for her manipulative deviousness - if she'd actually succeeded in killing Leon and the first trial was effectively her vs Makoto then she could well have made my top 3.