Tear Jerker / Ar tonelico Qoga: Knell of Ar Ciel

• EXEC_FLIP_FUSIONSPHERE. Go on, try to read the translated lyrics and not cry.
• Listening to Au GuMu during the final battle could also have this effect, as you're hearing the Planet sobbing and crying while she sings.
• Finnel's breakdown in her Cosmosphere. She at first attacks Aoto to make him go away, but eventually she collapses into his arms and bawls her eyes out over her past.
• The bad ending, wherein not only do both Saki and Finnel die, Tyria never awakens, and the entire thing is a deconstruction of Aoto being a Determinator as he repeatedly promised the heroines he would do everything to save them- even destroy the Guardian the party had failed with earlier- but can do nothing in the end.