Pinched this idea from the former BBC boards

[RossRoy]

Name 15 movies in which hacking a computer system plays an essential role.

1. WarGames
2. Firewall
3. The Matrix

[Najemikon]

Name 15 movies in which hacking a computer system plays an essential role.

1. WarGames
2. Firewall
3. The Matrix
4. Swordfish

[Touti]

Name 15 movies in which hacking a computer system plays an essential role.

1. WarGames
2. Firewall
3. The Matrix
4. Swordfish
5. The Net

[Jimmy]

Name 15 movies in which hacking a computer system plays an essential role.

1. WarGames
2. Firewall
3. The Matrix
4. Swordfish
5. The Net
6. Hackers

[Najemikon]

Name 15 movies in which hacking a computer system plays an essential role.

1. WarGames
2. Firewall
3. The Matrix
4. Swordfish
5. The Net
6. Hackers
7. Independence Day

[RossRoy]

Name 15 movies in which hacking a computer system plays an essential role.

1. WarGames
2. Firewall
3. The Matrix
4. Swordfish
5. The Net
6. Hackers
7. Independence Day
8. AntiTrust

[DJ Doena]

Name 15 movies in which hacking a computer system plays an essential role.

1. WarGames
2. Firewall
3. The Matrix
4. Swordfish
5. The Net
6. Hackers
7. Independence Day
8. AntiTrust
9. Live Free or Die Hard

[Achim]

Name 15 movies in which hacking a computer system plays an essential role.

1. WarGames
2. Firewall
3. The Matrix
4. Swordfish
5. The Net
6. Hackers
7. Independence Day
8. AntiTrust
9. Live Free or Die Hard
10. Ocean's 13

[Jimmy]

Name 15 movies in which hacking a computer system plays an essential role.

1. WarGames
2. Firewall
3. The Matrix
4. Swordfish
5. The Net
6. Hackers
7. Independence Day
8. AntiTrust
9. Live Free or Die Hard
10. Ocean's 13
11. The Net 2.0

Not really original but the game must go on 

[DJ Doena]

Name 15 movies in which hacking a computer system plays an essential role.

1. WarGames
2. Firewall
3. The Matrix
4. Swordfish
5. The Net
6. Hackers
7. Independence Day
8. AntiTrust
9. Live Free or Die Hard
10. Ocean's 13
11. The Net 2.0
12. 23

[Achim]

Name 15 movies in which hacking a computer system plays an essential role.

1. WarGames
2. Firewall
3. The Matrix
4. Swordfish
5. The Net
6. Hackers
7. Independence Day
8. AntiTrust
9. Live Free or Die Hard
10. Ocean's 13
11. The Net 2.0
12. 23
13. Sneakers

[lovemunkey187]

Name 15 movies in which hacking a computer system plays an essential role.

1. WarGames
2. Firewall
3. The Matrix
4. Swordfish
5. The Net
6. Hackers
7. Independence Day
8. AntiTrust
9. Live Free or Die Hard
10. Ocean's 13
11. The Net 2.0
12. 23
13. Sneakers
14. Johnny Mnemonic

[Jimmy]

Name 15 movies in which hacking a computer system plays an essential role.

1. WarGames
2. Firewall
3. The Matrix
4. Swordfish
5. The Net
6. Hackers
7. Independence Day
8. AntiTrust
9. Live Free or Die Hard
10. Ocean's 13
11. The Net 2.0
12. 23
13. Sneakers
14. Johnny Mnemonic
15. Tron

[Jimmy]

I suppose that the board is mine, since Karsten haven't said that my answer was wrong. So I go with something easy (I think).

Name 15 movies where the human have to fight against out of control animals. (just one rule : no sequel)

1. Jaws

[Touti]

Name 15 movies where the human have to fight against out of control animals. (just one rule : no sequel)

1. Jaws
2. Brotherhood of the Wolf