The 1970s was a time of pushing boundaries both in subject matter and technology. Many movies came w/ strong messages and challenged traditional thinking. It still happens today, but it was really shocking back then. Also, I think the term 'blockbuster' came about in the 1970s due to Star Wars in 1977.
Finally, the political stand by actors in the day wouldn't happen in today's world.
Favorites -
Patton - I have to say that I thought it was interesting that George C. Scott played such a revered American War Hero at the height of the Vietnam War, and Scott's political views were quite liberal, anti-war, IIRC.
The French Connection - Not really a big fan of the movie, but notable I think for being one of the 1st films to film an elaborate chase scene. Now quite commonplace.
Klute - I think Jane Fonda's performance as prostitute, Bree McDaniel is considered one of the best acting performances of all time. No one entertainment figure ever has / ever will generate the controversy that Jane Fonda did a couple of months after winning best actress by becoming 'Hanoi Jane'.
A Clockwork Orange - Quite groundbreaking at the time. Really disturbing imagery. Way ahead of its time in analyzing what the state has the power to do in curbing criminal behavior
The Godfather - One of the best films ever, but Sacheen Littlefeather's refusal to accept the award on Marlon Brando's behalf at the Oscars to expose the plight of Native Americans in this country was a big news story
The Exorcist - Also groundbreaking. Even in today's world, I actually think there would've been a call to remove some of the scenes. I saw this as an adult years later and couldn't sleep w/o praying!
Chinatown - Roman Polanski at his best as director. Mystery thriller w/ a theme of fatalism that always found a thread in his films: You can't ever win. Also broached the topic of incest. We also find out from Hollywood gossip that no one likes working w/ Faye Dunaway
One Flew Over the Cuckoo's Nest - The name Nurse Ratched became synonymous w/ sadist
Dog Day Afternoon - Al Pacino robbing a bank to get the funds for his partner to have sexual reassignment surgery. Ahead of its time because that would still be relevant today.
Rocky - The little guy w/ no resources could challenge for the top and make something of himself.
All The President's Men - Lesson in government corruption that no one seems to care about / take seriously anymore.
Network - There is a problem w/ the media and its interest in ratings over all else, sacrificing its integrity as a defender of democracy. Again, still very relevant today.
Taxi Driver - Robert DeNiro at arguably his best. It dealt w/ a really dirty side of NYC: Assassination, child prostitution (Jodie Foster was an amazing 12 yr. old actress). I wonder if that storyline would be created now, or if it would be considered too much?
Star Wars - My 1st PG movie as a 9 year old. LOL. My dad took me to the theater to see it for my birthday. Like most kids, I couldn't stop talking about it, playing w/ action figures and toys, trading Star Wars cards (anyone remember those?)
Julia - Fonda flick, but everyone got to see Meryl Streep for the very first time on celluloid in a smallish role! More interesting was Vanessa Redgrave's controversial Oscar speech after winning best supporting actress which elicited boos.
Coming Home - Along w/ The Deer Hunter, one of the 1st movies about the fallout from Vietnam. Fonda's 'I'm Sorry' to American society?
Norma Rae - Sally Field, formerly Gidget, the Flying Nun and Burt Reynold's muse in Smokey and the Bandit showed she could be a serious actress. Strong theme of unionizing should still elicit attention in today's world.
Kramer v. Kramer - Divorce flick that broached the issue - What if a mother abandons her child and the family. Traditionally, the mother is the nurturer and caretaker. Meryl Streep starts on the road to becoming a household name.
Close Encounters of the Third Kind - Also groundbreaking in that aliens don't necessarily have to be characterized as evil in a movie.
I never 'got' The Deer Hunter. Funny that Meryl Streep only took the role to be near John Cazale, her partner but got a Best Supporting Actress nod. Wow.