Ah yes, you have different tastes to me. BTTF and goonies are ok. I would have listed it swartz films, lethal weapon, aliens, apocalypse now, blade runner, die hard, hellraiser, scarface, terminator, Beverly Hills cop, coming to America, untouchables. Watched loads of films in 80s and 90s, was really a heyday for tv and film (and gaming and music). I would need to look at each one though as lots from 70s as well. Heck it’s all getting remade now (generally very badly) which says a lot.

Cannibal Holocaust 1980 in order to understand modern "journalists".

The Critters series. Sci-fi, b movie comedy involving murderous little hedgehog aliens.
Ghoulies. horror comedy with little monsters and a guy resurrecting his dead warlock dad.

Cutters Way

The Fallen 1998 Denzel washington murder mystery with possession.

Angel Heart

The Ninth Gate 1999 and Frantic 1988 both of those films have similar elements.Frantic is where A guy gets drawn into a conspiracy after his wife goes missing.The ninth gate is where the main character is tasked with finding some supernatural books in france which gets him chased.

The killing fields. One of the few movies to show the evils of communism.
Full metal jacket is also good, a war film without any obtrusive message.

Hm, my picks ... well, my favourites anyway:

1980's
The Return of the Living Dead
Poltergeist I & II
Predator
Evil Dead 1 & 2
Aliens
Airplane
The Thing
The Shining
Bad Taste
Tetsuo
The Fog
Day of the Dead
Piranha II
Leviathan
The Abyss
Conan the Barbarian
Conan the Destroyer
Anything with Jackie Chan and Sammo Hung
Most of John Woo's action films
Batman

1990's
Tremors I & II
Night of the Living Dead
Army of Darkness
The Blair Witch Project
Arachnophobia
The Ring 1 & 2
Silence of the lambs
Deep Blue Sea
Lake Placid
Predator 2
Braindead
Total Recall
Jurassic Park
Congo ... Tim Curry's genius role
Mars Attacks!
Contact
The Lost World: Jurassic Park
Batman Returns
Sniper
Twister
Dante's Peak
Anything with Jackie Chan and Sammo Hung
John Woo's action films

.... what I can think of right now.

Weekend at bernie's 1989

Weekend at bernie's 2 1993

Only american or french? Okay, some of my favorites are:

Cape Fear
Missing in Action 1-3
Maniac
Lone Wolf McQuade
The Octagon
The Protector
Crawlspace
Schizoid
Road House

Depends on what you like but I would say some personal favorites

-Indiana Jones trilogy
-Beetlejuice
-Star Wars OT
-Predator
-the thing
-Robocop
-Back to the Future trilogy
-Who Framed Roger Rabbit
-Blade and Blade 2 (the actual first R-rated and black superhero movie)
-Jurassic Park
-The Matrix
-The Mask
-Rush Hour 1 and 2
-Austin Powers 1 and 2
-Fight Club
-Total Recall
-Spaceballs
-Airplane
-Almost any Disney film (they were on fire then)
-Terminator and Terminator 2
-Home Alone

For weird sense of humour:
Delicatessen (1991)

For normal sense of humour:
Taxi (1998)

Several excellent choices have been mentioned.
Here are some less obvious gems:

The Hidden [https://www.imdb.com/title/tt0093185/]
Johnny Handsome [/https://www.imdb.com/title/tt0097626/]
Rumble Fish [/https://www.imdb.com/title/tt0086216/]
Valley Girl [/https://www.imdb.com/title/tt0086525/?ref_=nm_flmg_act_106]
8mm [/https://www.imdb.com/title/tt0134273/]
True Romance [/https://www.imdb.com/title/tt0108399/?ref_=nm_flmg_act_47]
Wing Commander [/https://www.imdb.com/title/tt0131646/?ref_=nm_flmg_act_43]
Salvador [/https://www.imdb.com/title/tt0091886/]
Cop [/https://www.imdb.com/title/tt0092783/]
Best Seller [/https://www.imdb.com/title/tt0092641/]
Body Double [/https://www.imdb.com/title/tt0086984/]
King of New York [/https://www.imdb.com/title/tt0099939/?ref_=nm_flmg_act_102]
They Live [/https://www.youtube.com/watch?v=zLQ2d89vCiw]
Repo Man [/https://www.imdb.com/title/tt0087995/?ref_=nm_flmg_act_89]
Slam Dance [/https://www.imdb.com/title/tt0093986/?ref_=nm_flmg_act_79]
Into the Night [/https://www.imdb.com/title/tt0089346/]
Absolute Beginners [/https://www.youtube.com/watch?v=IoScx5FUkas]
Sid and Nancy [/https://www.imdb.com/title/tt0091954/?ref_=nm_flmg_act_102]
Bad Influence [/https://www.imdb.com/title/tt0099091/?ref_=nm_flmg_act_35]
As Good as it Gets [/https://www.imdb.com/title/tt0119822/?ref_=nm_flmg_act_12]
Killing Zoe [/https://www.imdb.com/title/tt0110265/?ref_=nm_flmg_act_82]
Henry [/https://www.imdb.com/title/tt0099763/]
An American Werewolf in London [/https://www.imdb.com/title/tt0082010/?ref_=nm_flmg_dr_42]
Innocent Blood [/https://www.imdb.com/title/tt0104511/?ref_=nm_flmg_dr_24]
Raw Deal [/https://www.imdb.com/title/tt0091828/]
Payback [/https://www.rottentomatoes.com/m/1087648-payback]
The Keep [/https://www.imdb.com/title/tt0085780/]
Falling Down [/https://www.imdb.com/title/tt0106856/]
The Ghost and the Darkness [/https://www.imdb.com/title/tt0116409/?ref_=nm_flmg_act_36]
The Game [/https://www.imdb.com/title/tt0119174/?ref_=nm_flmg_act_35]
The Island of Dr. Moreau 1996 [/https://www.imdb.com/title/tt0116654/?ref_=nm_flmg_act_88]
Ravenous [/https://www.imdb.com/title/tt0129332/?ref_=nm_flmg_act_71]
The Young Indiana Jones Chronicles Series [/https://www.imdb.com/title/tt0103586/]
Miami Blues [/https://www.imdb.com/title/tt0100143/?ref_=nm_flmg_act_128]
The Hitcher 1986 [/https://www.imdb.com/title/tt0091209/]
The Blood of Heroes [/https://www.youtube.com/watch?v=qoz4mU_MHtQ]
Secret Admirer [/https://www.youtube.com/watch?v=cf_oOfCt4cU]

It'd be easier to suggest films not to watch, unless you're going to roll up with friends to riff them to death, seeing as the 80s and 90s were full of hits and the Disney Animation Renaissance.
Such as:
Mac and Me, a shameless ET knockoff.

Maximum Overdrive: What happens when Steven King is coked off his rocker.

A retelling of a biblical allegory on crank. Set in the future year of 1994!

Howard the Duck, because we all want to see a grotesque duck animitronic get horny, right?

Nukie. Another ET Knockoff.

The Garbage Pail Kids Movie, because trying to base a movie off a series of grossout trading cards was going to work.

Troll 2. No trolls will be featured during the feature presentation.

...And that's just covering the ones that Wikipedia bothered to list.

80's

The Road Warrior 1981
An Officer and a Gentleman 1982
Christine 1983
Kiss of the Spider Woman 1985
Platoon 1986
River's Edge 1986
Full Metal Jacket 1987
Say Anything 1989

90's

The Grifters 1990
The Silence of the Lambs 1991
Unforgiven 1992
Heavenly Creatures 1994
The Usual Suspects 1995
Fargo 1996
L.A. Confidential 1997