I think my favorite couple hasn't been mentioned yet: Giles/Jenny...or Genny...or just G/J. Man, I loved them! I remember how Buffy called Xanya her "light at the end of the tunnel" and all I could think about was how cool it would have been to have Jenny live and her Giles stay together; that these 2 adults were able to meet under all the chaos of the Hellmouth and have a life together.
I think the reason I love them so much is that it was written so well and felt real, never forced. Plus, Anthony Head and Robia LaMorte's chemistry was so tangible and fun to watch! I love how Giles used to be a scared and bored young man in college, so he turned into a badass, but then gets in so deep over his head with Eyghon that he does a 180 into the "sexy fuddy-duddy" we see in the beginning of the show. Really imagine the kind of life he had to live to get him from "ticking time bomb hates the world" guy to Mr. Bookworm. He comes to Sunnydale to tend to his charge as watcher. You can tell he's devoted his life to being a watcher and fulfilling his destiny so much that he probably gave up on having much of a personal life or finding someone that would be ok with a man who lives such a lifestyle. He is so "by the books" when we meet him; and then he meets Jenny who was able to get under his skin and break him free from his monotonous life as a watcher.
And I wish we knew more about Jenny's upbringing! What we do know is that she was raised by a gypsy family, and that at some point got into computers and was tasked with watching Angel. For all we know she had always fought with breaking away from her family and her duties to them (her sass would allow us to believe this is a possibility) and computers and technology gave her that outlet from tradition; but when she was tasked with the burden of watching Angel, she (much like Giles) owned up to her destiny to fulfill her duty to her family. Regardless of how she got there, she too was coming to Sunnydale out of duty, for the sake of others, not for love.
So when they do meet and fall in love, it's even more unexpected and beautiful. Both had their minds set on their task at hand, but they found each other: someone that knew what living on the hellmouth meant, someone that challenged them, knew their history and past and still wanted to be with one another.
What I love most about their relationship was that it was messy. His past came up to haunt them as well as hers. It wasn't simple. With both of them having such colorful lives leading them to Sunnydale, it was rewarding to watch them reconcile their pasts with themselves - and each other.
Another big thing about their relationship I loved was that Jenny loved Giles as the fuddy-duddy he was, not Ripper-Giles. The only other women Giles had relations with in the show were involved with him based on his Ripper-ness: Joyce when they were teenagers and Giles was essentially his Ripper alter ego; and it's obvious that his relationship with Olivia wasn't much more than 2 people reigniting an old flame: as soon as she found out about his life in the occult, she bolted. Jenny did back out and get her own space after Eyghon but she came back to Giles within a month, and was even apologetic about being so harsh to him.
With all that said, I reiterate that I would have loved for them to have stayed together through the series and be the "light at the end of the tunnel" as a little reminder that yes, in the life of demons and vampires, you may have to make sacrifices and be alone dedicated to your duty, but that doesn't mean you'll be alone forever.
Told you all I would gush :3
