No Future For You
Buffy the Vampire Slayer Season 8, Volume 2, consists of issues 6 through 10, and mainly centers around the character of Faith. Faith is written brilliantly and evil, and the art is wonderful.
The story has Faith going up against a rogue slayer, which has her reflecting a lot on her own evil days. Through flashbacks, Vaughan makes strong parallels between Faith's past and the main action of this story. Vaughan doesn't let us forget about the Scoobies, who are dealing with their own problems back at the Scottish castle. Another big plus about this story is that the Big Bad of the season is revealed on the final page of #9 (the conclusion to the "No Future for You" arc).
Also included in this book is a one-shot called "Anywhere But Here" - written by Joss Whedon). Artist Cliff Richards - the artist who drew many of the old Buffy comics - takes on art duties for this one issue, which shows Buffy and Willow having a very revealing heart-to-heart conversation ... while they go up against a demon that causes reality to buckle around it. This issue alone is worth the price, because not only is it the best example of Joss's writing, but it's also pays tribute to a disabled fan of the show who won a Buffy contest.
Overall, this isn't only a book that every Buffy fan should have, it's something that every fan of graphic storytelling should own. It's a perfect example of why this is such a great medium and how the comic book has evolved. It packs an emotional wallop, it's true to the heart of the show, and it's written by two great writers.