As there's bound to be a more definitive Best Live Acts In '07 thread a little later, for the time being let's list the contenders:
Off the top of my head, for me:
Also strong, but not quite:
The Go! Team
Yo La Tengo
This has been a great autumn, eh, cos I've still got The Ponys, Band of Horses, and others to consider.
Feel free to make your list as long as you wish, but kinda note as I have ie., you didn't see 40 best acts of the year, eh.