1. (can't believe noone's mentioned this one) The whole ending sequence with Archer. Seriously, that's what made him 100% my favourite servant. He's been beaten by Shirou, stabbed apart by Gilgamesh, and used up his allotted no-mana-source-still-alive time, yet he still turns up to be in at the end. Saving Rin from grail flesh thing, and the "Yeah, you could do that, but dodge first" line where he owns Gil. Seeing as the sun's behind him, the last thing Gil would see would be an awesome silhouette (that word never gets used these days () shooting a sword right between his eyes. Epic. As. Anything. I know folk have said Shirou v Gilgamesh, and yes that's awesome ("Got enough swords?"), but the whole sequence with Archer at the end is better.
2. Archer vs Shirou. Needs no explanation.
3. Lancer's death. The poor guy always gets killed off, but at least in UBW he got to make an epic ending to it - stabbing Kirei. Hell yes. Fate death was also quite cool. "Hey Lancer, kill!" "...LOL DIDN'T USE COMMAND SPELL, I'LL ATTACK GIL!"
4. Ilya's death. Berserker holding himself together on will alone, her crawling blind across the floor towards him, that flashback.... I came as close to crying as I ever do. (that's quite a lot, considering I don't even cry at funerals) I'm getting a little choked up just remembering it (
5. Caster/Kuzuki's death. Forget mindless killers, they had hearts. Kuzuki insisting on fighting on even after Caster's strengthening was gone, it was clear to everyone that he would die, yet he fought on for her sake. The guy was awesome whilst alive, and the "You already did" about dreams. So touching (
Honourable mention to Archer flashbacks.