I'm absolutely obsessed with Fairy Tail and Attack on Titan. I know they are way extreme but the character development in those just draws you in. Personally, it's extremely difficult to pick a favorite character in both of those mangas/anime. If I had to choose, I like Gray Fullbuster, Erza Scarlet, Juvia Lockser, Aquarius, Eren Jager, Mikasa Ackerman, and Levi Ackerman.