Lou
Scooby
With Spike and Buffy it's much more of the latter. However I don't think Buffy needed to go through what she went through. A lot of people talk about Spike and Buffy as the 'adult' relationship but I personally feel it's one way an adult relationship can go. We don't need to be abused and to be an abuser to learn how to grow up. In fact I think that's a naive, narrow assumption in itself.
That isn't why I think Buffy and Spike is more of an "adult" relationship. I see the actual violence part as a product as the "super power" game, not as a real part of the relationship. Heck, Buffy and Angel duked it out a bit too.
The part that makes it more adult in my head is 1.) Buffy let herself be actually vulnerable with Spike. She lets him in on her fears and hopes in a way that is a LOT more open than she lets herself be with Angel. She was mad at herself for it, but people often get scared when they let themselves be that open. They want to take it back.
2.) We are allowed to see more "REASONS" for these feelings. Buffy and Angel came across as very superficial. Other than the Halloween episode where Angel tells her that he didn't like women from "his time" because they were boring, there is no real talk about WHY they like each other. It comes across as very high school and "Angel is dreamy and slightly mysterious". Which is fine for high school, but not really an adult love type thing.
Spike does more chatting about why he likes her. And, in her own way, even in Season 6, Buffy gives clues for why she likes him. For one thing, by not seeing him as perfect she doesn't have to be perfect for him. She knows he's safe, she knows he's loyal, and she can be sad and scared and not the all powerful slayer for him. Which even as much as she tries to deny it, still comes through quite clearly through most of the season. Even just all the times she gives Spike another chance or tries to get him "back on the path" in those last two seasons. Things she gave up on with Angel in Season 2. Just...oh he's bad, let's kill him. Some is that she's older, but Spike also gave MORE of himself to her than Angel did. Angel kept himself oddly closed off even in S1.
That's what says it's more mature in MY eyes. Sure, she's older. But, it's more in the way she reacts to Spike and him to her. It's that feeling of being strong and tough on the outside, but having one special person that you can be vulnerable to and NEED. A person you can lash our at on a bad day and 5 minutes later fall in their arms and know they'll catch you.
It's touching. I've had some superficial relationships and I've had some real ones. Buffy and Angel remind me of me and MY highschool boyfriend. We're still GREAT friends. We even have daughters born 4 hours apart. And I love him dearly. But, he makes a MUCH better "brother" figure than boyfriend. We're a great team, we hang out and play darts well. And I know he will have my back if things get bad. But, our relationship is and always has been very "idealized". We don't see each other for how we ARE, just how we want things to be. We've SEEN each other at our worst, but there was no "being vulnerable" it was being vulnerable but keeping up a facade where we were trying to pretend we had everything under control. It's a friendship I would NEVER give up, but it's a far cry from what I have with my husband!