I'm a huge fan of zombie films and so I'll add these to the list -

28 Days Later, an absolutely classic british horror/shocker/wierd film involving britain being overrun by a deadly zombifying virus that infects humans through bodily fluids. It's just brilliantly executed and very, very dark. Highly recommended.

I also saw the 2004 remake of George Romero's Dawn of The Dead last night - I must admit I was pleasantly surprised. This is perhaps the only horror remake I can think of that comes close to the original, although it's a very different film (straight up action/horror rather than darkly comedic social satire), I must admit I almost enjoyed it more than the original which does plod along at times and tends to kind of hammer its point home. Compared to shitty horror remakes like Wickerman and Texas Chainsaw Massacre it's a definite winner.

On the horror/Alien theme I started with AvP, I must say Alien 3 is perhaps my favourite film of that series (certainly, I like it AS MUCH as the first two), which seemed to be heavily (and to my mind very unfairly) panned when it came out. Resurrection is shit though.

Steve Martin starred in a movie a few years back called "Novocaine," which didn't get much notice and generally lukewarm critical reviews. But I thought it was an excellent film noir twist about a dentist whose storybook life takes a weird left turn. Also starred Laura Dern and Helena Bonham Carter.