And then Yoji's even bigger Freak Out in "Trane" when he is forced to strangle his amnesiac former lover - and hear her declaring her love for the Evilutionary Biologist with her dying breath. The scream is epic.
Ken letting Yuriko go off to Australia without him.
Most of the last episode of Weiss Kreuz Gluhen qualifies, but in particular, the scene in which Aya calls his little sister from a phone booth across the street from her job, just to hear her voice, having removed himself from her life for her own protection. Somehow, although he hasn't spoken, she guesses that it's him and pleads frantically for him to talk to her, prompting him to ask simply whether or not she is happy.
It's even worse when he gets knifed and doesn't bother to defend himself because his killer is a kid.
"Omi, Ken, Yoji... Let's go together..."
Poor Asami in Gluhen, whose efforts to be a good and caring teacher to her students get her killed when she trusts the wrong person and Aya arrives too late to intervene.
Second-to-last episode of Gluhen, the whole sequence with the Temple of the Underworld crumbling and Youji telling the others "Home is where you guys are," when Omi begs for him not to die and Ken asks that they go home together. Aya's response is to smile and tell him they'll be waiting. Cut to sunrise and Aya is standing on a hill overlooking the school complex, waiting...
Weiss Side B is full of these:
When Ken is showing talking to Yohji, who once was his best friend and now doesn't remember who Ken is and when Omi says he found his place in life as Mamoru Takatori, and that he wishes Ken to find the place where he belongs. He just lost two of his only friends, and yet he can't help but think he should be happy for them. It's even more heartbreaking when Ken goes to Aya and says he wants to stay by him, specially knowing that Aya abandoned him in Gluhen.
Another one with Ken is when he finally breaks down and, while kicking a soccer ball, says hardest thing for him is being close to his dream, yet not being able to reach it. I'm a sucker for Ken, but the way he confess this to Aya of all people, while managing not to cry - damn, it made me bawl like a baby.