This is an interesting question for me to ask because as anyone who reads this journal knows, I kind of hate Buffy/Angel. I think they have no chemistry and Angel's creepiness is frequently romanticized - and even when it is brought out in the open, like in the soulless Angel arc in S2, it's quickly stuffed back in the box with most of the characters treating Angel and Angelus like two different people (even though there are enough hints that this is not the case). Also, I can do messed-up, dysfunctional, abusive relationships (*waves at Buffy/Spike*), but for some reason I have a really hard time with the massive power imbalance in a relationship between a teenager and a very adult adult. And in a very fannish way, I resent the so many Buffy/Angel shippers actually think their ship is healthier and less bad then Buffy/Spike (sometimes to the point of vilifying Buffy/Spike shippers). I mean, I'm not gonna defend Buffy/Spike on any real world level, but please. Buffy/Angel is just as bad - and arguably worse, since the ickiness is portrayed as more acceptable and romantic.
And yet. The Angelus arc in BtVS S2 was a thing of beauty, and definitely the first thing that really sold me on the show. I like Buffy and Angel's dynamic as exes. And I love Buffy/Spike - a relationship that would have been completely different without the Buffy/Angel backstory. Becoming a Buffy/Spike shipper, ironically, helped me appreciate Buffy/Angel.
So: Here are the top favorite Buffy and Angel scenes from this non-shipper perspective. I say "Buffy and Angel" instead of "Buffy/Angel" because some of these scenes are not romantic.
From fifth favorite to most favorite:
5. Their final, wordless goodbye in Graduation Day, Part 2. OK, so it's telling that I have their break-up on this list, but seriously, I like this scene. Angel tells Buffy he's not saying goodbye - in keeping with his frequently paternalistic attitude towards their relationship, in keeping with the Bangel angst dating back to S1 that they have to stay away from each other due to the impossibility of their love making any interactions much too painful and much too tempting. But he can't resist. And Angel is on the taciturn side, so his goodbye is wordless. Wordless and distant, no talking or touching.
4. Possessed by ghosts in I Only Have Eyes for You. The gender-swap, the intensity of Buffy's playing of James. I have a lot of issues with Grace apologizing to the kid who threatened her with a loaded gun, but still the compare and contrast between Buffy/Angel and Grace/James is fascinating - especially in terms of Buffy's guilt and perception of herself. And the hint that maybe, maybe Angel does still have love for Buffy in his heart.
3. Their cemetery scene in Forever. This is the only scene that Mylie (the Bangel shipper who made the post I linked above) and I both have on our lists. *Points to icon* One of the differences between dating-Angel-Buffy and post-breakup-Buffy is that the latter actually can interact with Angel on an equal level - she's not a little girl any more. (Forever bitter than Angel stalked and slept with a teenage girl and then dumped her for her own good when she was finally old enough to be considered an adult and, y'know, consent to sex). One of the dynamics of teenage Buffy's interactions with Angel was that she (thought she) could be a little girl around him, instead of a slayer weighed down by responsibilities or the oldest child of a single mother. In Forever, we see that she feels like she can open up to him about how overwhelmed she is, and accepts his comfort and reassurance. Ironically, the kind of thing she never felt comfortable doing with Riley. But there's a different feel to how Forever Buffy interacts with Angel compared to high school Buffy. S5 Buffy isn't as naïve - and when she asks Angel if he could stay "forever", she knows it's a fantasy - unlike Bad Eggs Buffy who saw only Angel in her future. As I've said previously, later seasons Buffy understands that there is an element of fantasy to their relationship that teenage Buffy didn't get.
2. The reveal of what Angel did to Drusilla in Lie to Me. Buffy insists she can take the truth - she has no idea. Angel's past is horrifying, and when Buffy says she's not sure if she can trust him she doesn't get how little she really can. Even as late as Enemies and Earshot Buffy chooses to focus on her jealousy of Angel's connection to Faith over the possibility that Angel and Angelus might be the same. In Angel's speech there's foreshadowing to what he will do to Buffy - even a hint of how creepy their relationship is now. But Buffy doesn't know. Hearing Angel talk about Drusilla upsets her, but it will be nothing compared to the reality of meeting an obsessed and soulless Angel.
1. The sword fight in Becoming, Part 2. "Now that's everything, huh? No weapons... No friends... No hope. Take all that away... and what's left?" "Me." Never not a classic. Angel getting back his soul a bit later and sharing the grossest kiss ever before Buffy stabs him and sends him to Hell does not make my list, nope.
So on my list we have one Evil!Angel scene, one Evil!Angel and Buffy possessed by ghosts scene, one break-up scene, one post-break-up scene, and one extremely unromantic scene from when they were actually together…although it is the first time she tells him she loves him. It's telling of the hidden depths that the relationship has that when Buffy first tells him she loves him, she also says she doesn't trust him…and quickly learns just how horrifying his secrets are.