Best:
There Will Be Blood
No Country For Old Men
Wall-E
In Bruges
Let the Right One In
[REC] (it was shown here this year, so this counts)
The Orphanage

Worst:
Indiana Jones and the Very Awful Cinema Experience ("fuck, wow, i'm swinging with monkeys" ::gush::)
Diary Of The Dead (what was this about, tax evasion or something)
The X-Files ("if you woke up this morning and thought hey i wonder what scully and mulder are up to right now, then this film is for you and the other 6 people in the world like you")
Airlines vs Fred Astaire 2: Requiem

Anything I've left out I probably haven't seen, because whenever I watch a film I instantly place it into a 'best of year' vs 'worst of year' bracket, because that's the kind of twat that i am.