Don't forget Starship Troopers! No trash list is complete without it, even though it is only 22 years old.
Not sure this should be considered Trash, but i loved the 1984 Dune adaptation with a great cast: Sting (Feyd) and Patrick Stewart (as Gurney) in it, and must mention Sean Young as Chani who of course went on to Blade Runner).
The original B&W 1950s "Day the Earth Stood Still" with Michael Rennie, and a young Steve McQueen in The Blob!
https://youtu.be/_g5vFms1kkY
Top trash pick might be "Logan's Run", with Michael York and Farrar Fawcett. I think "The Island" might have been a remake of Logan's Run.
I could go on and on... The original "The Thing from another World, 1951.
Soylent Green with Charlton Heston is pretty bad.