I love this ep and mostly because of the Giles/Anya interaction. I'd been shipping them for a year before it aired and when I saw them, kiss, I almost fell off the couch. I still feel that way whenever I watch it.
As the episode progresses, they all begin to fall into their usual patterns and relationships, based on what they feel, not what they know. Spike and Buffy fight vampires together, Buffy and Dawn realise they are sisters. Willow and Xander figure they are dating but soon Willow realises she prefers Tara.
And all through this, Giles and Anya are together, bickering with a heat Anya and Xander never, ever have, fighting, breaking their "engagement", and making up with a big dramatic kiss that lasts until the moment the spell is broken.
They were so meant to be.
Everything ends on a sad, sad note, Giles flying away, Tara packing and leaving, Buffy and Spike kissing at the Bronze -- and yes, it's not a happy kiss -- but nothing can spoil my golden glow.
A question that has plagued me for years: Amnesiac!Giles says of Spike, "You do inspire a particular feeling of familiarity and disappointment." Why disappointment?