The Hays Code ended in 1966, and some started to take advantage of the extra freedom. Some used it stupidly, but there were some amazing movies… I included a couple of documentaries.
1967 (in order, like everything else I list)
The Incident
Hombre
In Cold Blood
Titicut Follies
Cool Hand Luke
Belle de Jour
The Two Of Us
Warrendale
Poor Cow
The Stranger
Mouchette
Le Samourai
The Graduate
La Chinoise
Guess Whose Coming To Dinner
Bonnie and Clyde
2 or 3 Things I Know About Her
1968
The Swimmer
Kuroneko
High School
Shame
Ole Dole Doff
Hell in the Pacific
Mr. Kinky
Secret Ceremony
Rachel Rachel
A Place For Lover
Petulia
If…
1969
They Shoot Horses, Don’t They? (my #4 all-time)
Salesman
The Happy Ending
Midnight Cowboy
Boy
The Learning Tree
A Gentle Woman
That Cold Day in the Park
This Man Must Die
A Married Couple
Easy Rider
My Night At Maud’s
Blind Beast
Burn
Kes
The Passion of Anna
The Wild Bunch
Tell Them Willie Boy Was Here
Last Summer
Katzelmacher
The Damned
If we’re talking reaction against the Hays Code, or even just its repudiation, it’s hard to choose better examples than Bonnie and Clyde and Midnight Cowboy. Both were brilliant and influential.
As an aside, the Hays Code was a US thing. So I’m not sure why you’ve included movies like Belle du Jour, If, and The Damned in your list.
1967
*Billion Dollar Brain
Branded to Kill
Casino Royale
The Good, the Bad and the Ugly
The President’s Analyst
Quatermass and the Pit
The Stolen Airship
Weekend
*
1968
*Danger: Diabolik
Destroy All Monsters
The Lost Continent
Night of the Living Dead
Performance
Spirits of the Dead
Targets
2001
*
1969 Goyokin
Horrors of Malformed Men
Latitude Zero
The Valley of Gwangi
The Wild Bunch
Z
The OP asks for favorite movies from 1967 - 1969. These are mine, in alphabetical order:
Female Demon Ohyaku
Goyokin
Have Sword Will Travel
Kill!
Once Upon a Time in the West
One-Armed Swordsman, The
Planet of the Apes
Quick Draw Okatsu
Samurai Rebellion
Valley of Gwangi
Zatoichi: The Blind Swordsman 15: Zatoichi’s Cane Sword
One of the standard SDMB nerd favorites is Sebastian from 1968.*
Dirk Bogarde as the code breaker in chief. Susannah York as his new hire.
Great, early small role by Donald Sutherland.
Lots of fun.
And in terms of the late 60s, it does have the obligatory psychedelic party scene. Completely with a bit of nudity depending on the version.
While from 1966, the aforementioned The Russians Are Coming, the Russians Are Coming is fun. Jonathan Winters and Michael J. Pollard. What more could you want? Well, a sequel would have been a great idea. Oh, well.
That’s right, I checked to make sure. Unlike all the people posting 1970 films.
Bonnie and Clyde (1967)
Cool Hand Luke (1967)
Once Upon a Time in the West (1968)
2001: A Space Odyssey (1968)
Rosemary’s Baby (1968)
Charly (1968)
The Prime of Miss Jean Brodie (1969)
Butch Cassidy and the Sundance Kid (1969)