Sometimes I've thought that Buffy should've ended with season 5. I just always thought of B as a gal to go out with a bang, and what better way to end a series on a high note then with the excellent season 5 finale. Especially since the last two seasons were such big dissapointments.
That said, there are some good episodes in S6. Particularly in the beginning and the end, as the poster above me so well points out.
One thing I really like in the first episode, is the way they the schoobies had found a way of doing the slaying without Buffy, and how her death brought them together. The schoobies camraderie and character interations in the first ep was really nice. And I actually think that they shoulda waited to revive Buffy for at least another 4-5 eps... It would of been really interesting to see how they dealt with the loss of Buffy, and it coulda made an interesting 3-4 ep arc about the revival of the Buffinator.
But as a whole, S6 just feels like one long, drawn out study in character assassination, from depressed emo Buffy to Xander dumping Anya at the altar, to Giles being a fool and not looking after them when they most need him, to Dawn becoming a slut and cleptomaniac, to Buffy at the doublemeat palace, to Anya turning into a revenge demon, to Willow becoming a junkie and pshycho witch, and finally the character assassination of the more physical kind---the killing of Tara.
So I can't really say I like how all the characters are ruined in S6. That together with the lacking quality makes this season pretty much a train wreck.
I also really really hate the nerd trio. They're so annoying, idiotic and lame. I wanted the schoobs to hunt demons, and instead they have to go chase some juvenile geeks. The trio was definitely THE moment when I felt like Buffy had jumped the shark.
And one more thing I hated... the double meat palace. Not only was it incredibly stupid for Buffy to work there (she coulda hunted monsters for a living, or taken advantage of her super powers, or asked Spike for help (which is what I would've done in her place)). But those stories were also really awful in every way.
And than another thing I didn't like... the almost complete lack of scooby interaction. Everyone is on their own, and the old schooby chemistry seems to be completely gone in this season. There is an episode where they are trapped in the house, I rather liked that episode actually cause it's like the only ep in S6 with any substantial schooby action.
And finally, if you like Buffy/Spike, then you might be disappointed with how they are threated in S6. Maybe you had hoped for at least a little romance and genuine intimacy, but it all seems to almost right away become a destructive affair where they abuse and degrade each other over and over. As somewhat of a Spuffy fan, I have to say that while some of the Spike/Buffy material was nice, pretty soon it's like it's all about the boink and nothing of the heart and romance. And also, their relationship ended way to soon---like after seven eps compared to Angel's and Riley's seasons of fullfilled shipping material. The way it ended was also really horrible: Riley---the guy who had abandoned Buffy in a really awful fasion and without saying goodbye---comes storming in to town like a knight in shiny armour and plays with Buffys feelings despite him being married. And then the monster eggs, the worst plot element of all time, it doesn't make much sense at all. I mean what does Spike need with a million bucks if all he ever buys is some booze and smoke? And if he didn't know what the eggs was, then why could't buffy forgive him, cause all the schoobies screws up at one time or another. And also, wasn't it big bad Spike that she fell in love with in the first place?
So in ending, the season redeems itself somewhat with the evil Willow arc, but not enough to make up for all the mediocre episodes and general crappiness of S6.