I borrowed the complete series on DVD from MartinOh of #afp fame, and I have to say, I'm extremely impressed. It has all the classic Whedon touches. It appears cinematic despite being a 45 minute TV show. It has beautifully rendered characters, played by brilliant character actors (I was somewhat worried that I wouldn't be able to shake the images I got of the cast members who'd appeared in Buffy and Angel, but they were fantastic). It has jokes weaved around complex and engaging plotlines. Did I mention I'm impressed?
*goes off to watch some more*
*goes off to watch some more*