I mean the characters you like before you read/watch the anime/novel/manga, and you still like them or like them more after finishing them.
Krul Tepes from
Owari no Seraph
Wammu, his character design made me like him at the start of the show, and after finishing jjba part 2, he became one of my favorite characters in the jojos series

Chino Kafuu from gochiusa.
There are a lot of characters in other shows that also made best girl call within the first two episodes of the show, but I'm not exposed to enough anime outside the actual show itself to be able to consider someone the best until I actually learn who they are. Examples include magumi katou (saekano), sayaka miki (madoka), yuu koito (bloom into you)