A ranking of the anime most likely to induce fits of tears in the viewer provides some choice sad, sad anime.
1. Mahou Shoujo Madoka Magica
3. Angel Beats!
4. Ano Hi Mita Hana no Namae o Boku-tachi wa Mada Shiranai
6. Code Geass
7. Gundam Seed
9. Natsume’s Book of Friends
See also the top 10 tearjerker anime for a similar ranking, albeit one based on a completely different set of anime fans.