I agree with previous posters about:
Mr Klein (Joseph Losey, director)
Lacombe Lucien (Louis Malle, director)
Very strong, very well made films set during the Occupation of France.

Max Manus is a great movie as well.

Flame and Citron is about the Danish resistance. But yes, it is a great film.

Soldier of Orange (Dutch)
Black Book (Dutch)
Ivan's Childhood (Soviet/Russian)
Flame & Citroen (Danish)
A Generation (Polish)
Kanal (Polish)
Ashes & Diamonds (Polish)
Rome: Open City (Italian)
Army of Crime (French)
Ballad of a Soldier (Soviet/Russian)
The Cranes Are Flying (Soviet/Russian)
The Ascent (Soviet/Russian/Belarusan)
A Man Escaped (French)
My Way Home (Hungarian)
Germany Year Zero (Italian)
City of Life and Death (Chinese)
And the following films aren't totally about WWII, but rather the Spanish Civil War of '36-'39 (which, like the Second Sino-Japanese War of '37-'45, was really a precursor to what was in essence the same struggle anyway):
Land & Freedom
Libertarias
Ay, Carmela!
La Voz Dormida
The Devil's Backbone
L'espoir (French)

I have them all and yes all are excellent.
"Eye of Vichy", the dvd, while not actually on the Resistance, does a give a fine overview of what they were up against in France during the time.
And another dvd is "La Bataille du Rail" whcih shows French railway workers sabotaging Nazi supply trains.

About the Dutch resistance I especially liked:
Soldier of Orange
Flame and Citron
Black Book
All were excellent.

Just saw this thread and thought I'd recommend Kanal, an early Andrzej Wadja movie about a faction of the Polish resistance during the Warsaw uprising's aftermath.

The book Das Reich by Max Hastings. The resistance tries to slow down a German army division as it travels from south west France to fight the Allied forces in Normandy. True story.

This message has been deleted.

Le chagrin et la piti (the sorrow and the pity) is a superb 1969 documentary about occupied and Vichy France featuring loads of interviews with Resistance members, ex German soldiers, politicians and even a former member of the SS. Woody Allen is a big fan and his character famously took Annie Hall to see it in the film of the same name. It is a fascinating look at France during WW2, told from all sides.

Marguerite Duras'
La Douleur
. It's a mix of fiction and non-fiction and I don't know about how much is/is-not true or not but I found it a fascinating first person account of the resistance and also an interesting perspective of France just after Liberation.
"a va by me, madamea va by me!"

The Red Shoes

If you're looking for academic history (i.e. fairly weighty, complex, and non-popular), check out Robert Paxton's "Vichy France: Old Guard and New Order," which is a landmark 1969 book on occupied France that has informed everything that's come since. More recently, H.R. Kedward's "In Search of the Maquis: Rural Resistance in Southern France" (1993) is an excellent book that discusses why men joined the Maquis (bands of fighters who hid out in the countrythink the Spanish rebels in Pan's Labyrinthas opposed to the urban resistance groups commonly seen in the movies) and how they carried out operations against the Germans.
One of the problems that you tend to run into while studying the resistance is the lack of good sources because they obviously didn't write anything down or keep any records of what they were doing, lest the Germans get their hands on those records and compromise everything.

See a film called Monsieur Klein dir. by Joseph Losey and featuring Alain Delon. The focus is not on the French Resistence, although it does figure into the story, but the film presents a pretty stunning image of the nightmarish, bureaucratic menace of occupied France.

This message has been deleted.

The film
Lacombe Lucien
(or some similar spelling) deals with these events. A teenage boy in rural France wants to be in the Resistance. The adults reject him as too young, so he joins the Nazi secret police and collaborators insteadwith mixed results, betraying the Resistance organization that rejected him.
This film was not intended to be about history so much (the director said he wanted to set it in Mexico originally, but the repressive gopvernment there at the time rejected this project) as about human nature. Why people from many different "backgrounds" are so easily swayed by authoritarian power and how they sometimes become the instruments of very bad acts. (And the ambiguous intersection of the personal and the political in human lives.)
Since the US is bombing the crap out of several third world countries right now, and feels very morally empowered to do this, perhaps this film is relevant to today's world too.BW

Is Paris Burning?
, directed by Ren Clment, deals with the various factions of the Resistance forcing the Allies' hand in liberating Paris the book is more successful than the film, but if you run the DVD with the French-language track and English subtitles, it works a
lot
better than the dubbed version.
Clment's first film was
La Bataille du Rail
, about the Resistance work done by French railroad workers.

Lacombe Lucien is about collaboration but really worth watching.

It's been a long time since I've read these books BUT
Soldiers of the Night, by David Schoenbrun, Dutton, 1980, a CBS correspondent's history of the French resistance
A Night of Watching, by Elliot Arnold, Scribner's, 1967, as the Nazis crack down on Denmark, the Danes sent the Jews living there to Sweden overnight
I've also got a paperback somewhere called The Danish Resistance but can't find it to get the publication info; more if I can find itHappy reading

Dutch director Paul Verhoeven has just made "Black book", which is a very interesting piece, showing the ups and downs of the Dutch resistance during WWII.
Melville has also directed "Le silence de la mer" in 1949 a very good and impressive film, although very simple.

This message has been deleted.

I recently saw a very good film about the French Resistance - within the Paris filmmaking community (!) - by the great Fr. director Bertrand Tavernier, called SAFE CONDUCT (or, LAISSEZ PASSER in Fr.)

Oh, I wasn't. I am actually English, so I tend to find any point of view fascinating, but thanks for those reccommendations, and I will look them up.
When the world is run by fools it is the duty of intelligence to disobey

This message has been deleted.

This message has been deleted.