Angel beats and school days are both tragic.
I consider Clannad (and Clannad after story) to be a better anime though; even though it doesn't quite fit the definition of a tragedy.
Edit: I wouldn't recommend watching School days if you like being in a good mood though.
I consider Clannad (and Clannad after story) to be a better anime though; even though it doesn't quite fit the definition of a tragedy.
Edit: I wouldn't recommend watching School days if you like being in a good mood though.