Going purely on the film trailers, I'd most like to see Shaun of the Dead.
I'm unlikely to get around to seeing either before it's shown on TV though, because I'm just not a massive movie fan.
I really liked the Lord Of The Rings Trilogy and just had to see the others after seeing the first one because it was all so well done, but bar such movie extravaganzas, I rarely go to the cinema at all.