I definitely know where you're coming from. I've only had a few animes fully impact me emotionally, but the one that pretty much impaled my heart, as cliché as it may sound, is CLANNAD. My heart still ruptures when I see those scenes and I have seen them countless times.The other would be Code Geass. When it finally ended I wasn't exactly sad, I just felt really empty. It was a mindblowing experience for me.