As Adventure Time is practically my favorite show right now, I thought I'd rank the characters in the order of my preference. Note: I am excluding characters in the Fionna & Cake franchise.This is only my opinion. Possible spoilers.
20: Ricardio the Heart GuyRicardio was the main antagonist of his eponymous episode along with "Lady & Peebles". Being Ice King's heart, he is clearly unstable and has plans that always fall through. Ricardio, however, is much more witty and cunning than the Ice King, managing to smooth-talk Princess Bubblegum and managing to avoid suspicion of being evil (well, with the exception of Finn). That being said, he does show some of the Ice King's old traits, and at times he was a rather odd character to be honest, wanting to rip out PB's heart and marry it. His best moment, however, came when his voice actor (George Takei) says his famous catchphrase "Oh My!"
19: ShelbyShelby is the rarely-seen worm that lives in Jake's viola. Though his only major appearance is arguably in "Mystery Dungeon", he still makes minor appearances in many episodes of the show, ranging from at the beginning of "What Was Missing" to denying Jake entry to the Citadel in "Wake Up". Though he is rarely noticed in Adventure Time, his appearances are often humorous and interesting, with the show being slightly different without him.
18: Hunson Abadeer
The so-called lord of evil is also the father of Marceline. Prompting her to sing the "Fry Song" at the beginning of "It Came from the Nightosphere", he is shown to be very rational. At times, however, he has been shown to be more empathetic and sympathising, such as when he hears his daughters song. He is deeply caring of Marceline and, in more recent episodes, is far nicer than he had previously been...however, this may only be towards Finn, Jake and Marceline.
17: Cinnamon BunDescribed by Princess Bubblegum as "half-baked", Cinnamon Bun was dim-witted, clumsy and childish. However, during "The Red Throne", he appears to be more brave and intelligent, becoming "fully-baked". Cinnamon Bun also had a short attention span, such as in "Apple Wedding", when he completely mishears Princess Bubblegum's instructions. Cinnamon Bun is always very unintentionally funny and humorous, and has cameos which can often add to the humor of the episode.
16: Earl of Lemongrab
Lemongrab is the first of Princess Bubblegum's "gone wrong" experiments. Being extremely weird, obnoxious and high-strung, the Earl of Lemongrab often acts extremely erratically in the most mundane situations. Acting as a dictator in more recent episodes, he has progressed as a character to be more bizarre and dysfunctional. Lemongrab is often a somewhat pleasant addition to the episode, especially during his most prominent and funny roles.
15: BillyBeing Finn's idol, Billy is a strong and brave character. He is noble and heroic, and his words often carry great gravity when he speaks. Though he is now deceased because of the Lich, his early appearances show just why Finn idolises him. His last appearance, in "Billy's Bucket List", is arguably his most significant role, revealing that Finn's father is still alive.
14: Magic ManUndoubtedly the biggest jerk in Ooo, Magic Man was banished to Earth after causing a number of problems on Mars. His magic pranks are often evil with an unusual sense of humor to them, such as when he turned Finn into a foot for helping him in the first place. Obnoxious and selfish, Magic Man is definitely the most unusual character in the series, though he isn't one that you'd like to encounter.
13: PrismoPrismo, I believe, is someone who's willing to take one for the team. In "Wake Up", he allows himself to be killed in order to grant Finn and Jake access to the Citadel. Prismo isn't a particularly noticeable character in the series, only appearing in five episodes in total, however, his humble appearances and selflessness prove he is a considerate being, albeit a powerful one.
12: Lady RainicornThough barely any of us understand what she is saying (excluding those that already speak Korean), Lady Rainicorn is a character summed up almost completely by her actions. Though her character is one of the most vivid designs, her laid-back personality show she is another different and imaginative character.
11: Tree TrunksA kind and considerate character, the southern Tree Trunks is mostly famed for her delicious apple pies. She appears to have very strong morals, though at times, she can be naive (seriously, she thought she'd stolen her own apples?) Tree Trunks is a character whom sounds older than she is though can act way younger. She is one of the most normal and calm characters of the series, though at times, she can prove to be a challenge for the residents of Ooo.
10: GunterGunter is the Ice King's personal servant, following him around. He is mischievous, however, as he has the unusual urge to break bottles. Described by Hunson Abadeer as "the most evil thing he's ever encountered", Gunter can be reckless and destructive, being careless about his actions towards other people. Gunter is a very dark character, as shown in "Reign of the Gunters" when he stole the Ice King's Demonic Wishing Eye and nearly destroyed all of the Candy Kingdom. Gunter's age, sex and other miscellaneous information are yet to be revealed, however, he has still proven to be entertaining, if, at times, a little odd.
9: Flame Princess
The evil daughter of Flame King became Finn's girlfriend after Incdendium. At times petulant and untrusting, she is very quick-tempered and very much like a teenager, making her very relatable to a lot of Adventure Time's audience. Though towards characters like Finn she can be more sincere and trusting (though not after "Frost and Fire"), she is intense, and uncontrollable, making her actions very unpredictable.
The weird thing about BMO for me is that I always thought BMO was a girl. As it turns out, BMO is genderless (though for the purposes of this I will call BMO 'he'). Nevertheless, BMO is a kind and caring character, though he "does weird stuff when no one's around", as shown in "Five Short Graybles". BMO has a friendly personality, and is especially protective of Finn and Jake, as shown in the episode "Incendium". Despite BMO's unusual side, some of the best episodes of Adventure Time are attributed to him.
7: The LichThe Lich, I believe, is the most evil being in all of Ooo. He is smart, cunning and deceitful, tricking Finn into helping him destroy all life in Ooo. His sole goal is to eliminate all life, and he will stop at nothing until that goal is accomplished. His arrogance and single goal have, at times, been his downfall, as he initially dismissed the Ice King as a fool, though he would eventually cause his demise in "Mortal Recoil". The Lich is the ultimate antagonist of Adventure Time, and has proven to be a worthy opponent.
6: Lumpy Space PrincessLSP is the vain, rude and often extremely ignorant teenager. Like Flame Princess, she is a teenager, and displayed several traits of adolescence, as she is often disrespectful to her parents and very arrogant. She craves attention and will often push others aside for her own desires. She can, however, display times of emotion, such as in "The Monster", when she sympathises with the villagers and gives them sandwiches which were meant to be eaten by her. Though she is bratty, she is a friend of Finn, saying he's one of her only true ones. Her character can provide some hilarious lines, and add some extremely funny moments to the series.
5: Princess BubblegumA woman of elegance, Princess Bubblegum is the intelligent ruler of the Candy Kingdom. Being the love interest of Finn for the first few seasons provided some awkward and hilarious moments, even though she's several years older than him. A calm and generally happy character, Princess Bubblegum is also into science, trying different formulas to do a range of things from resurrecting the dead to making a sphinx to watch over the kingdom after her demise. Being a princess, her main goal is to watch over and protect the citizens of her kingdom, which she does with great pride and happiness.
4: Ice KingThough the Ice King is mostly an antagonist for the majority of Adventure Time, he is mostly just discarded as a minor nuisance, as his plans generally do not follow through and have some, or many, major problems. Though on the surface the Ice King is disagreeable and annoying, in episodes like "Holly Jolly Secrets" and "I Remember You", we find out that he is a much deeper character than we first thought. Formerly Simon Petrikov, the Ice King purchased a crown that caused him to slowly lose his mind, making his sanity deplete rapidly. His past (during the Mushroom War) is probably one of the biggest moments of Adventure Time, and sadly, the Ice King has no recollection of it at all.
3: Finn the HumanYes, the major protagonist on my list is only at number three. Finn is the brave, if a little naive hero of Adventure Time. As proven in "Memories of Boom Boom Mountain", he enjoys to help others, especially his main love interest Princess Bubblegum. His efforts to keep everything in order, especially in the episode "What Was Missing", are outstanding, and prove Finn is deservedly the main hero of the series. At times, however, we remember that Finn is still young, such as in "Ocean of Fear", when his fear of the ocean gets the better of him. Though at times overprotective, Finn is a righteous and heroic character, and will stop at nothing to make sure good is in the world.
2: Jake the DogJake is the laid-back, comical companion of Finn. With stretchy powers, Jake is one of the most funny and simply one of the best characters on TV now. Jake always helps and supports Finn, and despite giving some inconsistent advice, is always there for Finn. Though Jake is twenty-eight, he always acts very immature, as shown in "What is Life?" and "The Limit". Jake's dim-wittedness and ignorance have proven to be a problem for him, though usually with amusing consequences. An example of this is in "Burning Low", where instead of paying attention to Princess Bubblegum, he dreams he is the new president. Nevertheless, Jake's comical appearances and laid-back persona show he is one of the best characters of Adventure Time.
Now, before I say number one, here are a few honorable mentions.
- Susan Strong
1: MarcelineI just love Marceline. She's such a deep character, but also such a fun character. Debuting in "Evicted!", she forces Finn and Jake to leave their home. Since then, she has grown to be good friends of Finn and Jake, though arguably her most famous relationship is with Princess Bubblegum, as displayed in the episode "What Was Missing". Though on the surface she's a mischievous rocker girl, we see over time that her character has developed among the episodes, such as in "I Remember You", where we are made aware of her past relationship with the Ice King. This is also explored in "Simon & Marcy", when we see what happens during the Mushroom War with them. One of the best points about Marceline is how she expresses herself through songs, particularly "The Fry Song" and "I'm Just Your Problem". Her seldom seen sentimental side can show that she's not what she appears to be when we first see her...she's a much deeper character with probably the biggest past of anyone in the show. Marceline is a sweet yet fearless character, and has provided the show with some of its most memorable moments ever.