Thief12And I've said it before here, but I'm probably one of the few who would put 28 Weeks Later above Days.
BadLieutenantOh, it's Alien vs. The Thing? Alien, unquestionably. The difference for me is in how the two movies present and define their characters. With The Thing, the movie rushes early on to establish its characters in the broadest strokes. As a result, they mostly end up being cardboard caricatures, and it's very clear from the beginning that Kurt Russell is our central antihero who's going to make it to the end, however ambiguous that ending may be. Alien never tips its hand that way. With Alien, the movie doesn't rush the character development. We're constantly learning more and more about them by how they learn about and react to the threat. In The Thing, none of the deaths or reveals were ever surprising or shocking to me because none of them involved Kurt Russell; he just reacted to them. In Alien, it's never really clear until the end who will survive, and there are a couple deaths/revelations that are really shocking.