I agree. I think Spike needs to make a guest appearance.
"I have heard a few complaints over the years, but then I just killed whoever spoke up, and that was pretty much that"
I'd LOVE to see Spike show up.
Evil Spike, lovesick Spike ("I may be love's *****, but at least I'm man enough to admit it") and especially Spike with a chip in his head.
SPIKE: Invite me in.
GILES: No. It's fairly unlikely.
SPIKE: Oh, damn it! look, I'm safe. I can't bite anyone. Willow, tell' em what I did.
WILLOW: You said you were gonna kill me, then Buffy.
SPIKE:
Yes, bad, but let's skip that part and get to the part where I couldn't bite you.
WILLOW: It's true. He had trouble performing.
SPIKE: Yeah, well, it looks like they've done me for good. Um...
BUFFY: What are you saying?
SPIKE: I'm saying that Spike had a little trip to the vet and now he doesn't chase the other puppies anymore. I can't bite anything. I can't even hit people.
...
Also loved later in the episode where he says they should leave Xander behind because "It looks like he's about to drop and I think I can eat someone if they're already dead."
THAT is the stuff I want.