How about...

The King's English

Billy Elliot

Four Weddings and a Funeral

Shaun of the Dead

I also like many BBC series, like:

Sherlock

Dr Who

Top Gear

Gorden Ramsy's Kitchen Nightmares

Lord of the Rings

Entirely in British English

Lots of different accents and dialects from various parts of Britain

A lot different kinds of old-fashioned, formal and poetic language, but not much informal language

There are currently three Lord of the Rings movies and two (soon to be three) Hobbit movies

Harry Potter:

Entirely in British English

The language is extremely informal. Characters will often omit words or syllables. 

There are eight movies.

James Bond:

The main character, James Bond, has always spoken British English, but other characters are often American or European. Depending on what film you choose, you'll likely find a mixture of native and non-native accents

There are apparently 23 movies

Gladiator/Avatar/The Wolverine/Clash of the Titans

The main characters in all of these speak with an Australian accent. Unfortunately there's virtually no film industry in Australia, but 'badass' characters in American movies are often played by actors with Australian accents. They'll usually pronounce words in an American way however, whereas Australians generally pronounce words like the British do (ex. Australians say 'tom-AH-to' instead of 'tom-AY-to', but in American movies they'd say 'tom-AY-to' in an Australian accent). Note that this doesn't apply to all Australian actors (ex. Chris Hemworth plays Thor with a British accent, even though he's Australian).

Most of the other characters are usually American.

Incidentally, there is a version of Macbeth set in Merlbourne starring Sam Worthington. It's still in Shakespearean English, but all the actors have Australian accents.  The result is hilarious: http://m.youtube.com/watch?v=0mU3QOYUq2o

Sorry, I had to delete the movies in American English I had listed to get under the character limit. I'm using a phone so I couldn't copy what I wrote.

I think the vast majority of English movies are in American English anyway, so you shouldn't have trouble finding any.

I forgot, the series "Downton Abbey"

"The Kings Speech"