I'm so sorry to do this to you.
I was about to do a bunch of research, maybe even a top ten. I started the preliminary thinking, got through a few musicals I'm familiar with without much luck - Guys 'n' Dolls, Hello Dolly - then it hit me.
La La Land is about the artist's struggle, and how taxing it is to follow your creative dreams. All the tough choices and sacrifices you make, all the heartbreak and dedication to the goal. I don't have to do research to know that's the closest story to my own daily struggle.
Short Answer: The Phantom of the Opera also speaks to me, on account of the fact that one of my testicles hangs a full testicle-length lower than the other. Is there such thing as a Testicle Mask? Did I just write the name of my impending musical?
Fuck it. I'll do the Top Ten anyway.
Top Ten Musicals That Are Most Like My Life
10) Guys 'n' Dolls - 'Cause I got the girl. And that was lucky.
9) Hello Dolly - 'Cause I look like a lonely, middle-aged, meddling woman.
8) Cats - 'Cause I suck at being what I'm supposed to be.
7) Oh What A Lovely War - 'Cause I think war is just the tits.
6) Singin' in the Rain - 'Cause I love A Clockwork Orange
5) West Side Story - 'Cause I can dance fight.
4) My Fair Lady - 'Cause I have to 'My Fair Lady' my wife every time she wants to leave the house.
3) Chicago - 'Cause CM Punk!
2) All That Jazz - 'Cause I read it wrong.
1) La La Land - 'Cause look at the mess I've made.