It's happened more times than I can count.  Someone brings up "Lover's Walk," or the Spuffiness factor of Season 5, or, most recently, the undead lovers of "Heartthrob."  Inevitably, someone pops up on a discussion list with the perennial dumbass question:

"Ummm... wait... vampires can't love, right?"

::bangs head against keyboard::

The first real comparision we ever got between the souled and unsouled version of a vamp was when Angel went all Angelus-y hour years ago, and we know what a bastard he was then.  Although he was obsessed with Buffy, there wasn't anything there that could have been defined as "love."  Ergo, many assumed- completely ignoring Season 2's evidence to the contrary in the form of Spike and Drusilla- that a soulless creature is incapable of love.  End of story.

Hmmm... but what about Spike's hundred-and-eighteen year relationship with Dru, or his feelings for Buffy as they have been demonstrated over the past season?  What about James and Elizabeth, the lovebirds of over two hundred years?  Or vampire cowboy Lyle Gorch and his wife, Candy... anybody remember them?  Oh, but hey, they must be anomalies, 'cause look at what bastards Angelus and Darla are!

Well, we've seen both Angel and Darla in human form (Liam and second-season temporarily-human Darla respectively) and we know that they weren't given to, well, caring about much of anything but themselves.  Neither one of them, in any incarnation, has been especially good at expressing and processing emotion, unlike Spike, who has worn his feelings on his sleeve since day one.  In "The Trial" and "Heartthrob," each left the other to die; if carelessness is a feature of vampirism, how does one explain Spike's patience with Dru through all her less-than-sane moments, his concern for her injuries received in Prague, and his willingness to join forces with the enemy to protect her?  If Angel is capable of affection now that he couldn't feel before, I suspect a century of agonizing self-scrutiny and reprioritizing had something to do with it, rather than the application of a soul.    The truth is, no, not every vampire loves.  But not every human does, either.  If you want an example of healthy emotion in vampires, Angelus and Darla are probably not your best bet.

The "soullessness=inability to love" argument usually bases itself in the assumption that love is somehow a fundamentally "good" emotion.  And if you're talking philanthropic love for all of mankind, perhaps it is.  But we're talking about romantic love, about the intense affection and passion one person has for one other.  And love is not always pretty- those who have experienced it know that it can be unpleasant, wrenching, and downright painful.  (Look at the perennial Spike and Dru comparision with Sid and Nancy.)  Add a demon into the mix, and things are bound to get messy.  Vampire love is not all hearts and flowers.  Well, sometimes there are hearts, but they're usually disembodied.

But so many people keep insisting that Spike and Dru didn't really love one another.  For crying out loud, what more evidence do you need?  This usually brings us to the "obsession" theory.  As in, "Spike and Drusilla weren't in love, they were just obsessed with each other"- obsession being the flip-side of love, the "evil" version of a "good" feeling.  Okay, for one: Drusilla was obsessed with Spike?  When?  She showed a lot of affection for him, but never obsession.  (Dru doesn't have enough of an attention-span for obsession.)  And yes, Spike was obsessed with Dru.  Before that he was obsessed with Cecily, and after that he was obsessed with Buffy.  All that proves is that Spike loves obsessively.  (Vampires do, in point of fact, have differing personalities.  Lack of pulse does not infer that they're all going to behave the same way.  What they have been informs what they will become.  Writing bad poetry becomes kidnapping your grandsire and stapling his hand to your beloved's becomes getting chained to a ceiling and beaten to a pulp by an obnoxious hellgod.)  Yet for some reason, his feelings for Dru were "obsession," whereas his feelings for Buffy, which manifested themselves in disturbing behaviors like stalking and mannequin-bashing, are becoming increasingly interpreted as "true love."  What, the quality of love is determined by the goodness of the beloved?  (A lot of Spuffy 'shippers are redemptionistas as well, which somehow suggests that being in love with the good guy somehow makes you the good guy...  ever heard of "opposites attract," people?) 

As Giles pointed out in "Bewitched, Bothered, and Bewildered," obsession is selfish; it gives no concern for the object of attraction, only a sick fixation on them.  Given that definition, Spike's feelings for Dru can't very well be dubbed obsessive at any point, and although his feelings for Buffy certainly began that way (remember his speech to Riley about the "better deal"?), they didn't stay that way.  If you'd asked me six months ago, I would have said that Spike is merely obsessed with Buffy; he has since proved otherwise;  his actions towards her have progressed from selfish to selfless ("Intervention" being the turning point most cited).  (Before you say it, "selfless" does not necessarily equal "good."  See my redemption essay.)  The fact is, Spike can love, and he does love.  Quite well, if not wisely.