"I'm Just Your Problem" is one of Marceline's best. And for those who feel that the song is too self pitying without letting Bubblegum say her piece, "You’re Your Own Problem" is an AU fan song where Gumball either gives a "reason you suck" speech or has a "reason you suck" debate with Marshall Lee, telling him that only he can fix his problems and culminating in a declaration of devotion and love.
Only two words can describe the party music from the beginning of "Power Animal": HELL. YES. Generally if there's a party going on, there's gonna be good music.
"Gonna show you who's in Charge here! (who's in charge here!) Gonna get my Point across here! (across here!)" Marceline's Boss theme, which sums up her back story, and her personality.
Young Lemonhope, born from candy and glue, creater of beauty, and ugliness too. Especially awesome since it's Bubblegum's first solo song. It doubles as sad as well: Lemonhope's journey shows that there was either another war or some form of disaster during his absence - this one appearing to have been extinction-level.
Marceline. Is it just you and me in the wreckage of the world?. What starts off as a somewhat comical (if off-beat) song about Marceline's frustration with the Ice King gradually turns into a full-blown Tear Jerker, revealing their tragic history and Simon's last thoughts as he suffers from Loss of Identity due to the Ice Crown. Easily one of the most hard-hitting songs in the whole show.
"Greatly appreciated", a heartwarming song played during Minerva and Martin's date and marriage life.
It might not be as popular as some of the other songs on this page, but "I Look Up To You" is easily one of the most emotional songs in the entire series.
"Time Adventure". "Time is an illusion that helps things make sense. So we're always living in the present tense. It seems unforgiving when a good thing ends. But you and I will always be back then." A beautiful heartbreaking lullaby BMO sings to both Jake and the audience, reminding all the longtime fans that though the story may end, it will always live on in our memories.
"Waving to You", the show's very last song, debuting in the credits to the Grand Finale instead of the usual tune "The Island Song" (since it was already played in its entirety during the ending montage); its emotional, bittersweet and melancholy tone combined with the title is pretty much a metaphor of the show and it's characters waving goodbye to us. It's especially an absolute Tear Jerker for people who grew up with this cartoon.