I'd say Ghostbusters. It's not necessarily the best movie ever (for instance two of my three favorite movies ever, Brazil and Once upon a time in America, are from the 80s), but, amongst all my most beloved movies from the 80s, it's the most blatantly 80-ish. It's the specific archetype of 80s awesomeness.

Because, you know, Buckaroo Banzai goes just a little bit TOO far.

Also, I almost said Men in Black. These films are so fantastically 80-ish, I'd have no problem to mention them here. I just happen to like Ghostbusters better.

The Right Stuff.

"Is that a man?"

"Youre damn right it is..."

Way too many to list, but one movie that really defines the 80s for me is The Breakfast Club.

Stranger than Paradise. 1984, Jim Jarmusch.

Blade runner
Falcon and the Snowman
The Hitcher
Once upon a time in America
Excalibur

EDIT: The Hitcher is very underrated in my opinion

Hands down, Robocop. Runners up are The Road Warrior, The Terminator, Commando, and Bloodsport

Two in the box, ready to go. We be fast and they be slow.

For me Ghostbusters 1 and 2, along with Gremlins 1 and 2, Willow, Never Ending Story and Back to the Future made my 80's in the movies.

What?! No one mentioned Ladyhawke or Dune? I also like Blind fury, among others, the list is just too big to place here.

I was wondering if someone would mention this. I was going to but you beat me to it! Another good 80's fantasy film is The Dark Crystal.

(mostly sci fi movies)
Bladerunner
Mad Max series
Commando
Alien
Terminator
Die Hard
Fullmetal jacket (me love you long time :)))

Saturday Night Beaver (1986)

The Dark Crystal.

Yes i know, but i actually like for a couple of reasons (sean young, the voice over that gives it a noir feeling,sean young, the cast, sean young, the mood, did i mention sean young :P ) Well i like the movie in general, even if it has little to do with the books.

Aliens (James Cameron, 1986)
Amadeus (Milos Forman, 1984)
Back To The Future (Robert Zemeckis, 1985)
Batman (Tim Burton, 1989)
Beetle Juice (Tim Burton, 1988)
Beverly Hills Cop (Martin Brest, 1984)
Big (Penny Marshall, 1988)
The Big Chill (Lawrence Kasdan, 1983)
Blade Runner (Ridley Scott, 1982)
Blood Simple (Joel Coen, 1984)
Blow Out (Brian De Palma, 1981)
Blue Velvet (David Lynch, 1986)
Body Heat (Lawrence Kasdan, 1981)
Born On The Fourth Of July (Oliver Stone, 1989)
Brazil (Terry Gilliam, 1985)
The Breakfast Club (John Hughes, 1985)
Broadcast News (James L. Brooks, 1987)
Brubaker (Stuart Rosenberg, 1980)
Bull Durham (Ron Shelton, 1988)
Can't Buy Me Love (Steve Rash, 1987)
Chariots Of Fire (Hugh Hudson, 1981)
A Christmas Story (Bob Clark, 1983)
The Color Of Money (Martin Scorsese, 1986)
Crocodile Dundee (Peter Faiman, 1986)
The Dark Crystal (Jim Henson & Frank Oz, 1982)
Das Boot (Wolfgang Petersen, 1981)
Die Hard (John McTiernan, 1988)
Do The Right Thing (Spike Lee, 1989)
Driving Miss Daisy (Bruce Beresford, 1989)
The Elephant Man (David Lynch, 1980)
Empire Of The Sun (Steven Spielberg, 1987)
The Empire Strikes Back (Irvin Kershner, 1980)
Escape From New York (John Carpenter, 1981)
E.T. The Extra-Terrestrial (Steven Spielberg, 1982)
Evil Dead II (Sam Raimi, 1987)
Ferris Bueller's Day Off (John Hughes, 1986)
First Blood (Ted Kotcheff, 1982)
A Fish Called Wanda (Charles Crichton, 1988)
Flash Gordon (Mike Hodges, 1980)
Frantic (Roman Polanski, 1988)
Fright Night (Tom Holland, 1985)
Full Metal Jacket (Stanley Kubrick, 1987)
Gandhi (Richard Attenborough, 1982)
Ghost Busters (Ivan Reitman, 1984)
Glory (Edward Zwick, 1989)
The Goonies (Richard Donner, 1985)
Grave Of The Fireflies (Isao Takahata, 1988)
Gremlins (Joe Dante, 1984)
Hannah And Her Sisters (Woody Allen, 1986)
Hoosiers (David Anspaugh, 1986)
Indiana Jones And The Last Crusade (Steven Spielberg, 1989)
Indiana Jones And The Temple Of Doom (Steven Spielberg, 1984)
Just One Of The Guys (Lisa Gottlieb, 1985)
The Karate Kid (John G. Avildsen, 1984)
The Killer (John Woo, 1989)
The King Of Comedy (Martin Scorsese, 1982)
Lethal Weapon (Richard Donner, 1987)
The Little Mermaid (Ron Clements & John Musker, 1989)
The Long Good Friday (John Mackenzie, 1980)
Manhunter (Michael Mann, 1986)
Midnight Run (Martin Brest, 1988)
Mississippi Burning (Alan Parker, 1988)
Mona Lisa (Neil Jordan, 1986)
My Left Foot (Jim Sheridan, 1989)
National Lampoon's Vacation (Harold Ramis, 1983)
Nausicaä Of The Valley Of The Wind (Hayao Miyazaki, 1984)
Once Upon A Time In America (Sergio Leone, 1984)
Platoon (Oliver Stone, 1986)
The Princess Bride (Rob Reiner, 1987)
Project X (Jonathan Kaplan, 1987)
Raging Bull (Martin Scorsese, 1980)
Raiders Of The Lost Ark (Steven Spielberg, 1981)
Rain Man (Barry Levinson, 1988)
Re-Animator (Stuart Gordon, 1985)
Real Genius (Martha Coolidge, 1985)
Return Of The Jedi (Richard Marquand, 1983)
The Right Stuff (Philip Kaufman, 1983)
Risky Business (Paul Brickman, 1983)
The Road Warrior (George Miller, 1981)
RoboCop (Paul Verhoeven, 1987)
Romancing The Stone (Robert Zemeckis, 1984)
Salvador (Oliver Stone, 1986)
Say Anything (Cameron Crowe, 1989)
Scarface (Brian De Palma, 1983)
Sex, Lies And Videotape (Steven Soderbergh, 1989)
The Shining (Stanley Kubrick, 1980)
Sixteen Candles (John Hughes, 1984)
Stand By Me (Rob Reiner, 1986)
Star Trek II: The Wrath Of Khan (Nicholas Meyer, 1982)
The Stunt Man (Richard Rush, 1980)
The Sure Thing (Rob Reiner, 1985)
The Terminator (James Cameron, 1984)
They Live (John Carpenter, 1988)
The Thing (John Carpenter, 1982)
Three O'Clock High (Phil Joanou, 1987)
Tootsie (Sydney Pollack, 1982)
Top Gun (Tony Scott, 1986)
Trading Places (John Landis, 1983)
TRON (Steven Lisberger, 1982)
The Untouchables (Brian De Palma, 1987)
WarGames (John Badham, 1983)
When Harry Met Sally (Rob Reiner, 1989)
Who Framed Roger Rabbit (Robert Zemeckis, 1988)
Willow (Ron Howard, 1988)
Witness (Peter Weir, 1985)