1) The Godfather (1 and 2)
2) Grease
3) Rocky, Rocky 2
4) Jaws
5) Close Encounters of the Third Kind
6) The Warriors
7) Death Wish
8) Saturday Night Fever
9) The Exorcist
10) The Deer Hunter
11) Taxi Driver

The Godfather 1 & 2
Saturday Night Fever
The Warriors
Coffy
Foxy Brown
Enter the Dragon
Halloween
The Kentucky Fried Movie
Rocky
King Kong
Star Wars

In no particular order

Superman
Rocky
The Excorcist
Smokey and the Bandit
Uptown Saturday Night
Cooley High
Carrie
Silver Streak

M*A*S*H
The Shootist
The Poseidon Adventure
Duel (TV Movie)
The Godfather
Airport
Harry and Tonto
Blazing Saddles
Young Frankenstein
Star Wars

These movies really made an impact when I first watched them, although some havent held up well over time. Some I still watch whenever I get a chance.
The Omegs Man
Soylent Green
Chinatown
Enter The Dragon
A Clockwork Orange
Dirty Harry
Deliverance
Death Wish
Klute
Vanishing Point
M*A*S*H
Blazing Saddles
The Longest Yard

1. Mean Streets
2. The French Connection
3. The Exorcist
4. All the President's Men
5. Saturday Night Fever
6. Carrie
7. The Getaway
8. The Fury
9. Dog Day Afternoon
10. The Deer Hunter

Apocaplyse Now
One Flew Over The Cuckoo's Nest

Rocky
One Flew Over The Cuckoos Nest
Summer of 42
Duel
Willy Wonka & The Chocolate Factory
Saturday Night Fever
Grease
The Deer Hunter
The Black Stallion
Brian's Song

These are all of my favorite 70's films:

1. "Saturday Night Fever"
2. "Grease"
3. "The Apple Dumpling Gang"
4. "Herbie Goes to Monte Carlo"
5. "Thank God It's Friday"
6. "Close Encounters of the Third Kind"
7. "The Buddy Holly Story"
8. "The Barefoot Executive"
9. "Duel"*
10. "Shaft"
11. "Shaft's Big Score"
12. "Shaft In Africa"
13. "Love Story"
14. "Willy Wonka and the Chocolate Factory"
15. "Superfly"
16. "Return of the Big Cat"*
17. "The Whiz Kid and the Mystery At Riverton"*
18. "The Whiz Kid and the Carnival Caper"*
19. "Menace On the Mountain"*
20. "Robin Hood"
21. "The Rescuers"
22. "No Deposit, No Return"
23. "Barry Of the Great St. Bernard"*
24. "Superfly TNT"
25. "The Black Hole"
26. "Star Wars: A New Hope"
27. "The Boy Who Stole the Elephant"*
28. "The Apple Dumpling Gang Rides Again"
29. "Pete's Dragon"
30. "The Aristocats"

*TV movie

- Airport 1975
- Animal House
- Apocalypse Now
- Beneath the Planet of the Apes
- Billy Jack
- Blazing Saddles
- Bound for Glory
- Car Wash
- Chinatown
- Close Encounters of the Third Kind
- Death Race 2000
- Death Wish
- Deliverance
- Dirty Harry
- Duel
- Earthquake
- Heroes
- The Enforcer
- The French Connection
- It's Alive
- Jaws
- King Kong
- Lenny
- Magnum Force
- M*A*S*H
- Meatballs
- Midnight Express
- Network
- Norma Rae
- One Flew Over the Cuckoo's Nest
- Papillon
- The Pink Panther Strikes Again
- The Poseidon Adventure
- The Return of the Pink Panther
- Revenge of the Pink Panther
- Rocky (and the sequel)
- Saturday Night Fever
- Silver Streak
- Slap Shot
- Smokey and the Bandit
- Soylent Green
- The Sting
- Superman
- Taxi Driver
- The Towering Inferno
- Two-Minute Warning (original version)
- The Warriors

The Exorcist
The Godfather 1&2
Carrie
One Flew Over the Cukoos Nest
Halloween
Animal House
Saturday Night Fever
Rocky
The Deer Hunter

A Piece of the Action
Cooley High
Saturday Night Fever (Yes, I love this movie)
Grease
Car Wash

The Godfather Part I & II
Halloween
Dirty Harry
The Texas Chainsaw Massacre
High Plains Drifter
Grease
JAWS
Rocky
Rocky II
STAR WARS

Midnight Express
Shaft
Carrie

Halloween
The Exorcist
Grease
Carrie
Willy Wonka and the Chocolate Factory
The Rocky Horror Picture Show
Cheech and Chong's Up in Smoke

Grease
Willy Wonka and the Chocolate Factory

Rocky (and the numerous sequels that were made in the 70's)
Halloween
The Bad News Bears
Grease
Young Frankenstien

Kramer vs. Kramer is one that hasn't been mentioned. I loved that movie.

Scrooge (w/Albert Finney) (70)
A Clockwork Orange (71)
Sleuth (72)
Play It Again, Sam (72)
Phantom Of The Paradise (74)
JAWS (75)
Love and Death (75)
Let's Do It Again (75)
Marathon Man (76)
Annie Hall (77)
Star Wars (77)
Smokey and the Bandit (77)
Any of The Pink Panther movies(w/Peter Sellers)
Animal House (78)
Grease (78)
Heaven Can Wait (78)
Superman: The Movie (78)
Foul Play (78)
The Black Hole (79)
ALIEN (79)
Manhattan (79)
"10" (79)