There are lots of reasons I could cite for enjoying Buffy.
The awesome theme music (!), the fun, genre-spanning monster-of-the-week format (am I alone in thinking The Gentlemen were just the creepiest?), the many, flawed and interesting female characters, the character development and related angst (why, Whedon, why?), the pop culture references and Buffy Speak. Just the fact that it's a trendsetting show centered on a strong female character (but not the bad kind) which is LGBQT positive (weren't Willow and Tara voted most believable lesbian couple on TV at the time?) with positive messages about female empowerment and personal growth. And Spike. Can't forget Spike.
All good reasons for liking the show, I grant you.
But for me, the real magic of the show is Giles. Or rather, what he represents.
I mean, Anthony Stewart Head is wonderful in many glorious ways. The stuffy englishman stereotypes he embodies, even as he fights evil and apparently has a punk rock past (I'll admit, as an Englishwoman, I enjoy a fellow Brit being awesome on American TV). His gorgeous voice, complete with the most BBC of BBC accents. His looks (he rocks the Hot Older Man thing, OK?). The affectionate paternal/avuncular relationship he develops with Buffy (awww).
But most importantly, he's a librarian.
True, magical libraries and their kickass staff are tropes that really do it for me (Lirael, anyone? The Unseen University?). But, I swear, it's more than that!
It's the fact that in at least 10% of nearly every episode (by my highly scientific, vague estimation) one or more of the characters actually hitting the books and doing their own research.
As a graduate, nerd and bookworm myself, that is something I can appreciate.
I've been thinking back over other shows and movies I grew up with, and I honestly can't remember many that actually feature the protagonists reading their way out of a conundrum. This being my go-to response to any problem, I feel people like me lack representation. (There was Belle, I guess, from Beauty and the Beast, but when did her reading habits ever actually help her in that movie?)
Sure, action or fantasy movies might feature a Gandalf or M to fill the hero in on what he (usually he, dammit Hollywood) needs to know.
But in Buffy we get to see the (time skipped) magic happen.
Like Giles, bless him, teaching the younger generation to use reference materials in every Race Against Time To Save The World. Let that be a lesson to us all: we need our public libraries. (Personally, I know where I'm heading when the zombie apocalypse comes.)
Not to mention the number of times said school library becomes a battleground. And if that isn't symbolic, I don't know what is.
Fun can also be had from the 90's computer technology making an appearance in the school. Though in all seriousness, I like that Willow and Jenny (alas) being computer nerds are a thing. Apart from the fact they're women (in STEM, people!), Whedon covers all his bases vis-à-vis research. Internet wisdom is out there. (You can believe. Just check your sources.) Not to mention his conscientious warning to younger viewers about web safety (poor Willow and her aborted online dating career).
And Buffy started a trend. From Harry Potter to The Girl With The Dragon Tattoo, characters everywhere in pop culture are turning to books (or Google) for answers. The hunt for information is suddenly dramatic (and filmable). Buffy made reading (and geekdom) cool(er).
(Not that nerds get off scott free. Jonathan and his clique are example enough of the dark side of geek culture. Well done, Whedon. There's some self-deprecation right there.)
In Buffy, as in life, knowledge is power. Sure, slayer strength and friendship gets the apocalypse-averting job done. But it's the library hours that make it possible.