I'm going to come to Angel's defence here. Some people like Joan might point to the fact that he should resist the urge to take Buffy and continue to fight. However for me his decision to die has always come across as a selfless decision.
When you think about what he was having to deal with I can't imagine anyone being able to cope. This wasn't a situation he could excape or move on from. The First was constantly tormenting him.
He'd already tasted Buffy in the previous season meaning he had a longing for her that he struggled to keep intact without the First's involvement. As a vampire his natural nature is to kill. You combine that with the First driving him insain I think the guy deserves at least some sympathy.
Yes, but nothing compared to what Spike goes through. He is driven thoroughly insane by the First, compounded by his newly acquired soul (and not yet having had sufficient time to adapt to the onslaught of guilt and remorse). Though, of course, comparing the two is like comparing "apples to oranges" as they say.
Ok...my ramblings on other stuff put out here:
Yes, everyone from Joss to SMG to James have all said that when Buffy told Spike, SHE DID MEAN IT! period.
Spike is not inherently "beneath Buffy" and she is not "dragged down to his level." We must all remember the man we see William was and the humanity of that man that remains within Spike, even without the presence of his soul. He is unique. His capacity for love as a soulless vampire is even beyond that of what we are shown of Liam's as a man. Spike is both a warrior and a lover. So is Buffy. Her life is fighting, but as the 1st slayer tells her, she is full of love. This is why I feel like they are so good together: they are equal parts lover/fighter. We see them regard each other with respect for the capable warrior they each are. When Spike is chipped, though, and cannot fight her, she starts really putting him down. Things change again, drastically, when she learns that he can fight her again (Smashed).
They both came out of their "relationship" better people. By the end of S7 (Chosen and after) Buffy is finally able to let down some of the walls she built up after what happened with her and Angel. Spike's unconditional love and acceptance of her allowed her to see herself through his eyes, not just hers. She has had major abandonment issues, along with the trauma of sending her first boyfriend to Hell. Spike has been searching for requited love since he was a mortal. Dru was not capable of providing that. Once he is ensouled, he is able to mesh the man and the demon. He becomes a champion who is worthy of requited love, which he then has from Buffy.
Worth is not something predetermined at birth; it is best determined by the choices we make and who we are inside. Buffy and Spike both make mistakes, but they are there for the other when they are at their lowest. I love how when one is weak, the other is there to hold them up, not drop them or fall down with them.
Also, on the "Buffy wouldn't kill Faith for Spike" thing...she sure looks like she wants to when she finds Faith flirting with in the basement in S7
😛 Though that wouldn't be FOR him, i guess.