Can't pick only 5...
My Top10:

1. The Thin Red Line

2. Mulholland Drive

3. District 9

4. 99F

5. The New World

6. Akira

7. Solaris

8. Babel

9. Sunshine

10. The Three of Life

also, It would be interesting to know the age of people answering... (would explain a lot).
Example: me, 30 years old.

1. The Empire Strikes Back
2. The Godfather
3. Pulp Fiction
4. Goodfellas
5. Rounders.

Well my number one, I am sure of it, for the top 10 mm maybe yeah they could be in order, the rest i just enjoyed them =)

1) One flew over the cuckoo's nest
2) Reservoir Dogs
3) Unusual Suspects
4) Cinema Paradiso
5) La vita e bella
6) The Deer Hunter
7) Blade Runner
8) Donnie Darko
9) The Godfather
10) 2001 Odyssey to Space

11) Aliens(2)
12)Eternal sunshine of the spotless mind
13) Pan's Labyrinth
14) Misery
15) Toy Story 
16) Lord of the rings (all)
17) Jurassic park 1 (nostalgia i know the music was so good)
18) The matrix
19)Star Wars (all)
20)Memento
21)Pulp Fiction (BRAIN DETAIL! hahaha such a good movie)

In no particular order:

1. Memento
2. The Godfather
3. The Good, The Bad, and The Ugly
4. The Matrix
5. The Lord of the Rings: The Return of the King

E.T.
Gladiator
Braveheart
Beauty and the Beast
The Land Before Time
Lord of the rings 1
Star Wars 5
Snow White and the Seven Dwarfs
Princess Mononoke
Shindler's List

There are so many awesome movies out there I decided to double my list.

Not in any order, and this is just off the top of my head

- Gran Torino
- Billy Madison
- The Naked Gun
- Shawshank Redemption
- Inception/Shutter Island (tie)

Other great movies: Inglourious Basterds, Aliens, No Country For Old Men, Batman Begins, American History X, Saving Private Ryan, First Blood, etc.

Horrible movies that are way overrated: The Godfather, Scarface, Monty Python and the Holy Grail, Casino Royale/Quantum of Solace, etc.

-The Matrix
-Spiderman 2
-How to train your Dragon
-Fight Club
-Kung fu Husle

While I typically dislike lists that are dominated by too recet movies, gotta admit you chose some of the best.

Thanks!

I grenerally flip flop between Pan's Labyrinth and The Wizard of Oz as my fav fantasy movie. I found Eternal Sunshine of the Spotless Mind to be simply amazing, and I also think it was probably one of the most underrated films of last decade (should've been more successful at the box office and a bigger contender at awards shows).

1) The Dark Knight
2) Transformers Dark of the Moon
3) Inception
4) Pirates of the Caribbean (Entire Series)
5) Star Wars (Entire Series)