Welcome to the Hellmouth: Not an overtly 'shippy moment (especially with Buffy still underage), this was where their partnership was born. As opposed to their first meeings in the library, this appeal to Buffy worked because instead of invoking duty or destiny, he simply showed her the truth of things and trusted her to do what was right.

Witch: (aka The Witch) Giles cradles Buffy in his arms, promising to save her. This episode was an early indication of his devotion to his Slayer. Seeing her life in danger sparked both fear and passionate anger, and his efforts earned him high praise from Buffy: "You saved my life! You were a god!"

Never Kill a Boy on the First Date: Seeing Buffy make the hard choice to break up with Owen, Giles shares a little bit about himself. He reveals that his being a Watcher was just as destined as her being the Chosen One, and he had just about as much say in the matter as she did. But they take comfort in the fact that they're in it together.

Nightmares: At Buffy's apparent death, Giles sees his worst nightmare come to pass: he was unable to protect her. When Buffy rises as a vampire, it's Giles' reassurance and support that convinces her to hold it together long enough to set things right.

Prophecy Girl: Seeing Buffy's death foretold in the Pergamum Codex, Giles is as shattered by the prophecy as Buffy is, but when she resolves to face The Master, she finds Giles ready to go in her place. It takes a sharp blow to the jaw to "convince" him to let her go, and she can't find the words to say goodbye... "When he wakes up, tell him... I don't know. Think of something cool. Tell him I said it."