Well...this is kinda hard. (note that overrated doesn't always mean a bad thing) Anyways...I think it would be between Flame Princess and Finn the Human. No offense but these two get talked about a lot and get WAY much credit than what they deserve. (I do like FP though just a heads up.)
I think its Marceline. I 愛 her and all, but if あなた compare her personal club's ファン with the others (shes got over 600 fans), あなた will definetely find her the most overrated. Plus the fact that so many people 愛 her, and there are so much ファン arts of her, probably passing other characters. The 次 would either be Flame Princess または Finn.
i hate to pick on the little dog... but jake's overrated... i mean, he's lazy, a thief, morally confused... he does things and has stupid ways of looking at things yet is very insanely popular... and FP gets a little too much credit than she is due...
Marceline. Every time she sings, I want to shoot myself.
Looking at her critically, she's a bit of a Mary Sue. She's all about emotions & her only weakness is the sun. I don't feel that her character has evolved much; she's もっと見る flat than well-rounded.
However, I absolutely adore "Gunter "Marceline; her childhood is far もっと見る interesting that anything she does as an adult.
Well, that's kind of the problem really...the only time Marceline piques my interest is when the series goes into her father-daughter relationship with the Ice King. For others, she's only interesting when she interacts with Finn または Bubblegum または her father. Not really interesting on her own.
Her sole purpose seems to be to sings songs & tantalize shippers.