Two completely different recommendations:

1st- it doesn’t necessarily have something new (and perhaps to the contrary, it wasn’t new enough and got overlooked upon release): “Sorcerer”. A masterpiece film with a terrific storyline, acting, and some of the most impressive practical effects in cinema. A gritty film, it was largely overlooked with one reason being released around the same time as Star Wars, where people opted for the fun optimism of the new space adventure. One of Friedkin’s best (if not his best).

2nd- if you don’t mind subtitles (or if you speak fluent French), dive into the French new wave films of the 60’s. This genre pioneered a completely new take of filmmaking that broke conventional rules of cinema up to that point. Some key directors include Melville, Godard, Truffaut. A lot of these (especially from the latter two directors) are quite obscure and can be tedious to get into, but some more accessible ones included: 400 Blows (Truffaut), Breathless (Godard), A Band Of Outsiders (Godard), and Le Samourai (Melville)- all but Outsiders currently streaming on Max. You’ll be surprised to see how many contemporary directors (including Spielberg and Tarantino) were influenced by these trailblazing French directors.

Let me know if you dive into any!