I found The Best Science Fiction and Fantasy of the Year (2007) a rather frustrating and glorious experience, depending on the story. On balance, I found too many stories simply not to my taste, so I skipped them. Of the stories that remained, I can heartily endorse each and every one of them as GOOD.
What was wrong with this collection? I found that too many of these stories weren't fantasy or science fiction stories, they were other kinds of story with fantasy or SF twists, usually at the end. While I don't call them bad stories, as each was written very well, they simply didn't strike me as belonging in this collection. You might think me narrow minded or intolerant or fussy or behind the times, and maybe I am each of these things, but I strongly disagree with the notion. I've read some pretty radical stuff in my day without blinking. This stuff wasn't radical, it was boring.
Even worse than boring was the sameness of all the stories. I could have sworn up and down that most of these stories was written by the same dull writer. The voicing came across like a machine had produced each story, each one using the same kind of pacing and technique. Unfortunately, without the engagement being in the stories, each one felt dull.
As for the good tales, they were a varied and engaging lot. I'll give a shout-out to some of my favorites. My criteria is that the story must work through its SF or fantasy element. If you can easily change the element while keeping the heart of the story, I don't consider it a SF or Fantasy story. Also excluded is any story which I've forgotten the plot for only a few days after reading it.
Three Twilight Tales - Jo Walton
These three, fairytale style stories, are just long enough to entertain and get their point across.
The Island - Peter Watts
A fantastic psychological hard SF story and a hard SF story at the same time.
Ferryman - Margo Lanagan
This is a very mythic tale, told well.
Dragon's Teeth - Alex Irvine
While I found the ending rather empty, and the structure rather awkward and forced at times, the story is a fine example of low fantasy which, when working well, works extremely well.
Mongoose - Sarah Monette and Elizabeth Bear
This is pretty much a medium-hardness SF tale. While I think that the story lacks a certain something and has a few pacing issues, I rather enjoyed everything else.
Before My Last Breath - Robert Reed
Mankind discovers an alien graveyard. Simple, yet mournful.
Joboy - Diana Wynne Jones
A boy discovers his own heritage the hard way. I think that the story ended a bit poorly, but it held me all the way through with no issues.
Utriusque Cosmi - Robert Charles Wilson
I don't know whether to call this a time travel story, a memoir, or a rationalized Theosophical universe. Honestly, it's all of the above and it just WORKS.
A Delicate Architcture - Catherynne M. Valente
This is a fairytale style story, about a confetion-made girl, one with great heart and heartlessness.
The Cat Who Walked a Thousand Miles - Kij Johnson
This was a simple animal perspective story, well done. This story screams "read me out loud." Interestingly, she had a second story in this volume which was too much even for me to read.