#angiles

Think about it. Angel was WAY too old for Buffy, and the fact that he preyed on an underage girl damaged his character in an unnecessary way. Giles is age appropriate. Sure, he's not 200+, but he's in his forties, which is reasonably mature in human years. Giles had already grown up and had had other sexual and romantic relationships. I don't think that there would be an emotional power difference age wise. Angel should have been a mentor to Buffy, which would have given him something to connect with Giles over. They're both also highly intelligent bookworms(I'll fight anyone who calls Angel dumb; he has a photographic memory and knows several languages, the fact that he has blind spots and isn't always smart about every single thing doesn't take away from that), and I bet Giles would love to hear about all the historical events that Angel was there for, and all the things he knows about other cultures. Angel would be very intrigued to learn all the things Giles knows about Slayers and demons from the Watcher's archives, and whatever other knowledge Giles might have accrued in his life. I can also see them liking the same music.

Giles could have given Angel his moment of perfect happiness, and Buffy would still have had a hard time killing Angelus because of how much Angel meant to Giles, and because Angel had been a mentor to her that she admired and cared for, like she did Giles. It could have been Giles who killed Angel at the end of s2. Buffy could have fought him until right before Angelus got his soul back, but she gets knocked out, and Giles intervenes right before Angelus kills her, but then he's reensouled. And it's Giles who has to make the heartbreaking choice of killing him.

Then, when Angel comes back in s3, Buffy still keeps it from Giles because she's afraid of how much it would wreck him emotionally, and she's also afraid that Giles might accidentally give Angel his moment of perfect happiness again and she doesn't want that to happen. Angel still leaves at the end of s3 because he also doesn't want to risk somehow achieving a moment of perfect happiness without sex, just from a moment of deep love, and he can't bear the thought of all the pain Angelus would cause, especially to the man he loves.