1900s- I don't think I've seen any from this period
1910S- 1 or 2 that I like
1920S- The Marx Brothers movies were good and a few others
1930S- The Decade had some good movies, but overall, not my favorite movie decade
1940S- Had many great movies like: Citizen Kane, Casablanca (I think)
1950S-Another Decade that had great movies!
1960S- Great Decade! This Decade also had a lot of John Wayne films.
1970S- seemed to focus a lot on the horror genre. Not a favorite of mine
1980S-A hit And Miss Decade For me. There were a few movies I liked but not many
1990S-see above
2000S-the only movies I'll watch from this decade are the Nickelodeon movies
2010S- Honestly, I can't be bothered to watch movies from this decade.

Overall, my favorite decade for movies, would have to be the 1950s

There were only 3 Marx brothers movies in the 20s, the majority of their films (at least the ones considered their classics) came out in the 30s.

My favorite decade is the 70s, and yes it does seem like there was focus on horror in the 70s, but I think that's mainly because so many good horror films came from that decade, and not just from the States, but it was also the best decade (I think) for Italian horror. Plus all of the made for TV horror movies that were rivaling their theatrical counterparts.
But the decade also has some of my favorite films from other genres including Harold And Maude and Spirit Of The Beehive, Murder By Death.

I can't think of any decade I don't watch movies from, all decades have something I enjoy.

There were only 3 Marx brothers movies in the 20s, the majority of their films (at least the ones considered their classics) came out in the 30s.

Coconauts was the only Marx Brothers film in the 20's!

Pre-1920's-Nothing much except Birth of a Nation...despite the uses of camera angles, the plot is NOT for my taste!
1920's-Not much...just The Jazz Singer and Coconauts.
1930's-One of the best movie years ever...especially 1939!
1940's-The movies started to wane once World War II ended.
1950's-There were some bad films in that decade...despite some great classics like Ben-Hur and Singin' in the Rain.
1960's-A mediocre decade for movies. It was regrouping from the 50's, but the touch wasn't there...yet.
1970's-The beginning of the blockbuster. Sometimes this decade was hit-or-miss.
1980's-I'm gonna say this is my favorite decade of movies. It had quality blockbusters like E.T., Back to the Future, Field of Dreams, Rain Man, The Goonies, Batman, and Who Framed Roger Rabbit just to name a few.
1990's-This is my second favorite decade of movies. Like the 80's, it had quality blockbusters like Goodfellas, Titanic, Forrest Gump, Jurassic Park, South Park, Good Will Hunting, and Independence Day just to name a few.
2000's on-This is where quality went down the drain...too many remakes, sequels, and movies based on a TV Show. What next...a movie based on all the ads on Geico?!

I grew up a kid in the 80's so I'm gravitating more to that decade, a lot of great movies came out in terms of comedy/action/horror/drama.

1920s(I haven't seen many of them):

The Cocanuts

1930s(I've heard about a lot of films , but have not seen many of them):

The Invisible Man
King Kong
Animal Crackers
Duck Soup
Gone With The Wind

1940s:

The Secret Life Of Walter Mitty
The Treasure Of The Sierra Madre
The Best Years Of Our Lives
The Big Store
Casablanca

1950s:

On The Waterfront
Guys And Dolls
Rebel Without A Cause
Some Like It Hot
Bus Stop
Singin' In The Rain
An American In Paris

1960s:

With Six You Get Eggroll
The Apartment
To Kill A Mockingbird
The Graduate
Yours , Mine , and Ours
How the West was Won
Beach Blanket Bingo
The Great Escape

mine are the 1980s
you got
back to the future trilogy
indiana johns trilogy
bill & ted 1 &2
the goonies

Here are some of my favourites


1930S- Wizard of Oz
1940S- Miracle of 34th street,Its a wonderful life
1950S- African Queen
1960S- The great escape,you only live twice
1970S- Star Wars,Assault on precinct 13,One flew over the coocoos nest,Blazing saddles
1980S- First Blood,Real genius,on golden pond,ruthless people,hopscotch,beverly hills cop
1990S- Marked Man,as good as it gets,on the edge of innocence,entrapment,monkey trouble
2000S- Frequency,Saw,Saw II,Firewall,romeo must die
2010S- None

My favorite decades for movies would be the 70's and 80's.

70's ;
Jaws
Close Encounters of The Third Kind
Somewhere In Time
The Poseidon Adventure
Up In Smoke
Duel
Scrooge

80's;
Back To The Future Trilogy
Ferris Bueller's Day Off
The Big Chill
Dirty Dancing
Raising Arizona
Poltergeist

1970s

John Carpenter's Halloween
Caddyshack
Blazing Saddles
Rocky
Alien

1980s

Fast Times At Ridgemont High
Bachelor Party
Friday The 13th
They Live
Police Academy
Space Balls

1990s

The Pest
Dazed and Confused
Encino Man
Halloween: Curse Of Michael Myers
Scream
Dogma
Mallrats
The Crow

My favorite decades for movies would be the 70's and 80's.

70's ;
Jaws
Close Encounters of The Third Kind
Somewhere In Time
The Poseidon Adventure
Up In Smoke
Duel
Scrooge

80's;
Back To The Future Trilogy
Ferris Bueller's Day Off
The Big Chill
Dirty Dancing
Raising Arizona
Poltergeist


Somewhere In Time is one of my wife's favorite movies.:)

The 80s Back to the future Raiders of the lost ark and all the John Hugh's teen movies

The 1960s, The 1970s, The 1980s and The 1990s because these 4 decades are the only decades ever to have plenty of more great classic films.