These were the punk rock movies that I remember from way back when. In addition to home video, there were still a lot of old movie theaters left. It was still possible to see many of these films on the big screen at a good price (as 'Midnight movies', cult films, etc.).
1) SID & NANCY (1986) Directed by Alex Cox of REPO MAN fame, I saw this at Bleeker Street Cinemas. As an outsider to the scene (I was a 14 year old skateboarder) I thought it was amazing. I even picked up the soundtrack album. Yeah, in retrospect it's not the greatest movie, but when I was a kid starved for punk rock it sure did the trick.
2) REPO MAN (1984) Another oddball one directed by Alex Cox. Music by FEAR, BLACK FLAG, CIRCLE JERKS, etc. Starring Emilio Estevez and Harry Dean Stanton. A period classic. Use to be a staple of late night cable TV all throughout the late 80's.
3) SUBURBIA (1983) Directed by Penelope Spheeris. Rented this one at my local video store. Music by D.I., THE VANDALS and TSOL. This one was studied, and REALLY gave a kid ideas on how to dress. Watched a million times!
5) TAXI DRIVER (1976) Martin Scorcese's classic starred Robert DeNiro as mentally troubled Vietnam vet Travis Bickle. This film would have a tremendous influence on the aesthetic and dark, sometimes mentally disturbed attitude of punk rock.
6) CLOCKWORK ORANGE (1971) Stanley Kubrick's futuristic dystopian tale of juvenile delinquency, criminality, behavior alteration and classical music. Again, an influence on the mental attitude and aesthetic of punk rock.
7) MAD MAX (1979) George Miller's tale of decay and chaos in the future Australian wasteland. There was obviously close study of subculture in the fashion and feel of this film.
8) ROAD WARRIOR (1981) George Miller's followup to MAD MAX featured an even more apocalyptic punk aesthetic and atmosphere that became widely mimicked in the subculture.
9) ESCAPE FROM NEW YORK (1981) John Carpenter's futuristic imagining of NYC turned into a maximum security prison, with the President of the United States held hostage within. Snake Plisken had a punk rock look.
10) BLADE RUNNER (1982) Many people feel Ridley Scott's 1982 masterpiece BLADE RUNNER is one of the first 'cyberpunk' films, a punk aesthetic brought to science-fiction scenarios. I agree. The film is brilliant.
11) RETURN OF THE LIVING DEAD (1985) A hilarious horror-comedy with a punk rock soundtrack and characters. Very 80's, very awesome.
12) ROCK N ROLL HIGH SCHOOL (1979) Roger Corman's campy RAMONES movie was widely available. Compared to other films of the era it came across as a bit cheesy, but it's aged pretty well. Good fun. Riff Randall!
HONORABLE MENTIONS:
You could buy copies of THE PUNK ROCK MOVIE (1978) and Lech Kowalski's DOA (1980) on videocassette in Manhattan record stores. DOA was released in the US by HIGH TIME Magazine.
TIMES SQUARE (1980) had a punk and new wave soundtrack that was widely available on vinyl. I found a copy of the 1982 film SMITHEREENS used at Blockbuster. It featured Richard Hell.
Bootleg copies of Sex Pistols' THE GREAT ROCK N ROLL SWINDLE (1980) could be found relatively easily for a price.
If you knew somebody higher up in the scene they might lend you their copy of DECLINE OF WESTERN CIVILIZATION PT. 1 (1981), UK DK: A FILM ABOUT PUNKS & SKINHEADS (1983) or ANOTHER STATE OF MIND (1984). These films were around but were harder to find.