This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Next to Normal
More than half the damn show.
"I Dreamed a Dance".
Diana: I know the night is dying dear, I know the day will dawn...
Gabe and Diana: The dancers may disappear, still the dance goes on.
Gabe: And on...
Diana: I'll wake alone tomorrow. The dream of our dance is through. But now until forever love, I'll live to dance with you. I'll dream, my love. I'll live, my love. And I'll die to dance with...
Then the ensuing "There's A World", in which Gabe tempts Diana to "join him" in a paradise.
Gabe: There's a world, there's a world I know. A place we can go, where the pain will go away. There's a world when the sun shines each day...come with me (He extends his hand to Diana, which she grabs without hesitation and is led off by Gabe.)
Dr Madden: (As Gabe is leading Diana away and repeating "Come with me") Goodman, Diana. Discovered unconscious at home. Multiple razor wounds to wrists and forearms. Self-inflicted. Sutures, gauze, antibiotics, sedated and restrained. Damn it!(A beat) ECT is indicated.
"A Light in the Dark"
"How Could I Ever Forget?"
"He was a baby when he died? I remember him older!"
"A moment of dread... someone simply said, your child is...."
"A Promise", especially to those of us who appreciate the nod to Nice Guys.
"Maybe (Next To Normal)"
Diana: (spoken) 17 years ago your brother died of an intestinal obstruction. He was 8 months old, the doctors missed it, your father and I didn't know anything. We were kids. Not much older than you. I'm so sorry we never talked about that. We wanted to give you a normal life, but I realize I have no clue what that is.
Natalie: (singing) I don't need a life that's normal, that's way too far away, but something next to normal would be okay. Yeah something next to normal, that's the thing I'd like to try, close enough to normal to get by.
The reprise of "Perfect For You"
"So Anyway" gets a special mention.
Diana: I loved you once and though, you love me still, I know, it's time for me to go...I loved you once and though, I love you still, I know, it's time for me to go. And so, goodbye.
The reprise of "I Am The One".
Gabe: But you've always known who I am.
Dan: Gabe. Gabriel.
Gabe: Hi, Dad.
"Didn't I See This Movie?"
"Wish I Were Here"
"Everything Else" is particularly heartwrenching. You can hear the desperation and borderline hysteria in Natalie's voice as she sings. The tears begin to creep up at:
You play 'til it's perfect,
You play 'til you ache,
You play 'til the strings or your fingernails break.
It really hits home when Natalie's voice breaks on "and there's nothing your paranoid parents can say".
Any time Diana opens her mouth. Alice Ripley sings every line like her heart is going to break.
Dan and Diana's conversation at last on the death of Gabe:
Diana: How did he die? ...Why? (A beat) WHY?
Dan: Diana! We didn't know. He was sick, but even the doctors missed it and we took him to the clinic, the specialist, the ER in the middle of the night. They said he had food allergies, they said 'babies cry'. We stayed up every night, you slept in his room. He cried and cried.
Diana: Until one morning he stopped...
Dan: Mine is just a slower suicide...
The line "For all the times that I've been told the way her illness goes, the truth of it is no one really knows." really hits because it's just so damn true.
"Just Another Day". Perhaps the song for Stepford Smiler families everywhere.
"I Miss the Mountains", and Diana's heartbreaking realization she's not only ignored Natalie, she's missed out on so much of life.
"My Psychopharmacologist and I" is quirky and funny, but there are two moments that just kick you in the gut:
Dr. Fine: Oh and one last thing - use may be fatal.
Diana: I don't feel like myself. I don't feel like anything.
Dr. Fine: Patient stable.
All of "Superboy and the Invisible Girl".
Take a look at the invisible girl/ Here she is clear as the day.
Please look closely and find her before she fades away.
Really hits home with anyone who's ever been overshadowed by a sibling.
"The price of love is loss, but still we pay... we love anyway."
The fact that it's Dan and Diana singing is what really makes it gut-wrenching.
"For all those years I prayed that you'd go away for good, half the time afraid that you really would." Especially if you have a dysfunctional relationship with your parents.
For more hard core fans, the line "Hi, Dad", alone could make them start sobbing.