Great thread!
I think my feelings on Buffy’s ships are that they each represent a stage of her life.
Bangel is the relationship she needed when she was growing in power. Her life was changing and growing so rapidly that she needed someone to anchor her and be a constant and static force. Angel is very much that. He’s a great pillar that Buffy can come to and talk with (and smooch) who is thoughtful, considerate, and well-versed in demonic matters.
Ruffy was the relationship she needed when she was uncertain of her power. Losing Angel and going to college was a massive change for Buffy. All of a sudden, nothing made sense anymore and the entire world got turned on its head. The formula of “go to library, research demon, kill demon, repeat” wasn’t there anymore. As such, she tried something new by dating a regular (ish) person with Riley. This was a new time in her life, and Riley was a new experience.
Spuffy, to me, is her relationship endgame. Spike and Buffy are both characters who started off vulnerable, came into serious power, and used that power for their own goals: Spike for evil and Buffy for good. They are, essentially, two sides of the same coin in a way that Bangel and Riley were not. Spike is loving, he’s loyal, and he’s devoted, even without a soul. When he gets his soul back, he retains these features and accepts centuries of trauma and guilt solely because it’s what’s best for Buffy. Yes, there’s Seeing Red, but if we discount Angelus’s terrible actions as “not Angel now”, can we not also look past evil deeds Spike did because it isn’t who he is anymore?
Personally, I’m a big Spuffy person, but I don’t think any of the three canon ships (or the several non-canon ones except for things like Buffy/Giles) are bad choices! BtVS has so many complex relationships and characters that it’s a real treat we can discuss such things in as much depth as we can! 😀