Anohana or the Makoto arc of Kanon. Both are sad. :(

Pokemon - The Movie when Ash gets turned to stone and Pikachu tries to bring him back to life.

I always cry when I watch that ****ing scene.

I felt really sad at the ending of any natsu de materru and angel beats

Gantz 2nd Stage. The ****ing bastard who wrote that manga is the most heartless person on the planet.

Katanagatari, very heartwarmingly sad.

I'll try 5 Centimeters per second and Sundays without god.

Also, I completely agree about the Makoto arc of kanon.