Lots of great suggestions so far. I love all "good" films.Film is the universal language, and it's fascintating to me to see what thwe world has to offer.
I'm going to stick with foreign language films, as I don't really think of movies from our cousins across the ponds (UK, NZ and Oz) as "foreign", and many of them do get a US release. But there are a ton of lesser known but fine movies from those countries and the subject probably merits its own thread.
I'll also applaud the mentions for
Let The Right One In - quite the best horror/supernatural thriller I've seen in ages, and possibly my favorite vampire film ever. It's not a typical horror movie, nor even a scary movie, although the issues it explores are very frightening indeed at times. The core of the movie is about human relationships and it explores the underbelly of adolescence through in a tender but totally unsentimental way. The pace is fairly slow to start, but the film is full of story information from the very first frames. You must be wiling to pay attention to get everything that's going on. If you like heavily plot-driven movies that tie everything up neatly at the end, then this film is probably not for you.
I'll also second the rec for
The Devil's Backbone, from Guillermo Del Torro. It's the first of a brace of this director's Spanish speaking "art" films set in Franco's Spain, the second being
Pan's Labyrinth, also highly recommended. It's a ghost story set in an orphanage. Political allegory, ghost story and murder mystery all in one, this is the film that put Del Toro on the map as an A-list talent (Pan sealed the deal).
As mentioned above, Alphonso Cuaron, (director of the terrific
Children of Men, Prisoner Of Azkaban and Y Tu Mama Tambien) was a producer on Pan's Labyrinth. Del Toro, Cuaron and Alejandro Gonzalez Innaritu (
21 Grams, Babel) are great friends and formed a production company - Cha Cha Cha Films. The very good
Rudo Y Cursi is their first production, directed by Alphonso's brother Carlos Cueron (in his feature debut).
Del Torro, Cuaron and Innaritu are highly collaborative and support each other's work - often coproducing each other's films, showing their work in prgress to one another etc. These three Mexican artists also seem to move easily between the independent/art film world and commercial cinema.
I think Innaritu's best film is actually 2000's
Amores perros (Life's A Bitch). That one knocked me out when I saw it in theaters. It's in Spanish, so qualifies for this thread.

I think Innaritu overreached with Babel myself.
If you liked The Devil's Backbone or The Others, you should seek out a Del Torro produced an ghost story entitled
The Orphanage (El orfanato) by first time director Juan Antonio Bayona. Not in the same league as Del Torro's Devil's Backbone or Pan's Labyrinth, it's still well done and worth a look.
It seems we have two subjects within this thread - classic foreign language movies, and more recent foreign releases that may have been overlooked.
I'm going to stick to more recent stuff to start, and here's some goodies you may have missed:
Kitchen Stories - From Norway and one of my favorite European directors, Bent Hamer comes this droll, gentle, offbeat and heartbreaking little movie. Kitchen Stories is ultimately an exploration of friendship. I won't give away the barely there plot - if you must know - got to imdb. There is a lot of story here, but little conventional "plot", the world shifts for the main character, but there are not any bog events. If you enjoy the work of Aki Kaurismaki you will probably enjoy this one too. (And do see
The Man Without A Past if you haven't already.)
After The Wedding - While we're in Scandinavia, let's not forget this great Danish film from Susanne Bier, who also directed the excellent
Open Heart and
Brothers, as well as the underrated
Things We Lost In The Fire. Our hero, Jacob Petersob, runs a failing orphanage in India. He returns to Denmark to solicit desperately needed funds from self-made millionaire Jorgen. The distracted businessman unexpectedly invites Jacob to his daughter's wedding, occurring that coming weekend. Jacob is drawn into a family drama whose surprising ramifications will be far reaching and devastating. Just...see...it. (Bier is associated with the Dogme school and uses some twchniques espoused by the group but she has far more heart than Von Trier.)
No Man's Land - Worthy of its Oscar for Best Foreign Language Film circa 2001. War has seldom been this absurd, funny or tragic. No one in this film - peacekeepers, combatants, the media, the top brass - gets a pass from Serbian director Denis Tanovic's sharp and ruthless eye. His nnext film was completely different, based on the Kieslowski script L'Enfer, a Medea like drama about 3 sisters and also worth a view. (Kieslowski of the famed "Trois Couleur" trilolgy - Red, White and Blue - Double Life of Veronique and Decalogue, also all recommended.)
Atanarjuat (The Fast Runner) - From Canada - in Inuktitut - this film is based on 2000 year old Inuit tribal legend. It's a stunning, gorgeous film with heroes and villains, a quest, beautiful young lovers, the rhythm of life and death in the arctic circle. The Fast Runner was made by an Inuit film company with an Inuit director, with native actors of immense courage and talent...and it's unlike anything you've ever seen before. Once you survive the initial culture shock you will be enthralled.
The Return - One of the best movies of recent years IMO, in whatever language, and an auspicious debut for its director Andrei Zvyagintsev.The story of two young Russian brothers being raised by their mother and grandmother in a coastal village whose father, suddenly returns after a 12 year absence. Attempting to reinsert himself into his sons lives, the father takes the boys on a fishing trip...and shows some disturbing tendencies...and what is he really up to? Things will never be the same again. This movie can be read as allegory, or parable...but it quite compelling on "merely" a human emotional level. I consider The Return is a must see film. Also recommedned is Zvyagintev's second movie,
The Banishment.
The Death Of Mister Lazarescu - Old Mr. Lazerescu feels unwell and calls an ambulance. After long delay, the medics arrive and take him to a hospital, whose doctors send him to another emergency room, who send him to yet another ER...the medics and docs can't agree how treat him...or when to treat him...and the night becomes very long for this old gent. A dark dark comedy... and while few of us have tangled with the Romanian medical system, anyone who's spent the night in an ER will find much to relate to.
Moolaade - Only a very wise and masterful a filmmaker such as Ousmane Sambene could have made this touching and devastating film about Senegalese village life. A group of woman in a small village stand up against tradition..female circumcision. Don't cringe, just see the movie...if you're man enough.
The Diving Bell & The Butterfly - American director/painter-/sculptor Julian Schnabel made this remarkably humane and gripping film based on the true story of Jean-Domimique Bauby, editor at French Elle who suffered a sudden massive stroke and foud himself a victim of "shut-in' syndrome while still a relatively young man. Unable to move any part of his body except his left eyelid, Bauby managed to communicate with his doctors and write a best selling memoir, completed shortly before his death. Not a depressing film, but a lyrical and tender one, as Bauby shares his rich inner lief and fantasies, as well as his terror and frustration.
Goodbye Lennin - In 1980s East Germany, a mother falls into a coma during the Cold War, only to awaken 8 months later after the fall of the Berlin Wall. Because mom's greatly weakened heart can suffer no shocks, son Alex determines to keep all momentous political reforms a secret...with hilarious results.
Surely everyone has seen
Delicatessen and
City of Lost Children by now, oui?
The Lives Of Others is just as good as its press, another instance of a film actually deserving its Oscar.
And now for some not so recent favorite movies that I feel are outstanding:
Raise The Red Lantern - and most anything else from director Zhang Yimou. Young Songlian becomes a the fourth wife of a wealthy older man, leaving her home for the sequestered harem in his mansion. Intrigue and drama ensue as the wives and concubines maneuvre for their husband's favor
and the limited power available to them. One of the most gorgeous films ever made.If you know Yimou from Heroes and House Of Flying Daggers see this - I also highly recommend this director's other early work:
To Life, Ju Dou and The Story of Qui Ju.Au Revoir Les Enfants - if this movie doesn't break your heart you have none to break.
Fanny & Alexander - Bergman masterpiece but not intimidating. Come in the theatrical release and the full miniseries version shown on TV.
Babette's Feast - French and delightful
Wings Of Desire - Classic, captivating, Wender's best is quite rightly his most famous film.
Antonia's Line - Lovely film about a woman rebuilding her family in Holland after WW2.
Eat Drink Man Woman - charming and funny family tale of three sistersand their widowed father, from Ang Lee, who was also in fine comedic form for
The Wedding Banquet, about a gay Chinese son living in America whose parents desire nothing more than to see him married...to a woman of course.
Open Your Eyes (Abre los ojos) - Twisty and sharp Spanish tale that was remade into the dismal Vanilla Sky. Don't hold that against this excellent movie.