What anime scenes are most memorable to you?

I've only thought about series, but here are the top five that are seared into my mind.

#5 Katanagatari

Having been pretty skeptical of watching this in the first place, I made it that far and did not see this coming at all. I was totally dumbstruck. I'm thankful that I didn't see this when it originally aired, because there was no way I would have been able to wait a month for the next episode.

#4 Mononoke

The exorcism sequences.

I would link the first scene, but the only high-quality sources I can find are on YouTube, and their video compression simply cannot do it justice. If you are interested in this show at all (and you definitely should be, it's truly a work of art!), don't try to find out too much, just go in blind.

This just blew me away when I first saw it. I still think of this anime as the benchmark for art direction, and any of those scenes could probably qualify as the best-looking clip I've seen in the animated visual medium, period.

#3 Shigurui: Death Frenzy

Irako Seigen vs. Iwamoto Kogan fight

Even without knowing how the details of this scene fit into the wider context of this near-masterpiece of a show, this video speaks for itself.

#2 Aku no Hana

The classroom scene.

This show is SO good at building tension, and this scene was almost as cathartic a release for me as it was the characters. At the end of this episode, I was just stunned. Lovely cinematography as well.

#1 Ghost in the Shell Stand Alone Complex: 2nd Gig

The Tachikoma are one of the best examples of character development I've seen in anime, if not the best. By the time this played out, I couldn't believe those silly little spider tank robots managed to make me shed a tear..

So, what are yours, and why? Please tag spoilers as necessary!