30 days of night was great except for the screeching noise the vampires made. It was beyond annoying, especially at the movie volume I like.
But the PQ was top notch.
I have only watched I am Legend on standard dvd...because I liked it so much I just purchased the Bluray version on ebay (sitting in my collection not watched just yet). I really liked the movie. Yeah, the CG enemy was a little over board, but I thought they did a good job and it was great near the end with the headbashing (for those who know what im talking about).
summary:
30 days of night = Rental (possible buy)
I am Legend = Buy
...but everyone is different.
