Both Angel Beats! and AnoHana are amazing!!! They are definitely in my top 10 favs. Im not usually one for sad anime, but they both did a great job at getting you to connect to the characters and feel invested in the storyline.

I have yet to see Clannad but I'm adding it to my list now :)

I definitely recommend Erased or otherwise known as Boku Dake Ga Inai Machi its pretty new. Amazing storyline that is quite unique in my opinion, definitely sci-fi/mystery and drama but does a great job at getting you to really feel for some of the characters. If anyone watches it or has seen it let me know what you think!!