This is a French film, based almost exclusively (but not entirely) in the city of Paris following a multitude of inter-connecting characters. The situation is that Romain Duris's character is diagnosed with a heart problem which could kill him even if he has a transplant. He tells Juliette Binoche (his character's sister, who has been distant) who then comes more into his life with her three children. The rest of the characters stem out from these two, from the market she shops in to the people Duris watches out of his window (as he puts it, the only thing that keeps him going).
The ensemble is very fine indeed - aside from the main two, Mélanie Laurent gives a nice performance as the object of Duris's desires, Julie Ferrier and especially Albert Dupontel do well as Binoche's grocers at the market ... and getting the opportunity to see comedy dancing from Fabrice Luchini is always worth the price of admission alone. One problem I had with the film was a lot of characters get together romantically in this film and only one or two of the instances were handled believably (many were just rushed and out of the blue) - the cast though do their best with it and do make you forget it even if it is initially jarring. Director Cédric Klapisch also has the luxury of completely wasting Maurice Benichou and Karin Viard in glorified cameos, but they are delightful in their few scenes.
Cinematically the opening of this film is quite wonderful, it's a visual treat. The film also has genuine moments of poignancy, my favourites all involve Romain Duris and some cannot be mentioned without going into the final moments of the film, but seeing him after learning of his condition phoning up a childhood sweetheart merely to say what she'd meant to him and later on having Binoche claim he's great with kids then seeing what he has them doing, coupled with the final scene involving him and Binoche provides an emotionally real core to the film.
It seems almost impossible to me to talk about this film without mentioning Magnolia : Episode II - Attack of the Clones (that's Crash to everyone else 
). Coincidence is a thing I in general find a very lazy screenwriting tool when used generically. It's obvious that coincidences happen in life. Where I take issue with it cinematically is where the coincidence is the only thing that gives the film meaning or creates the drama (as opposed to something like When Harry Met Sally where it's a coincidence that they meet years later in a bookstore, but that is something realistic and merely something to allow us to carry on with the story). This film, like Crash does rely on the coincidental ties of all the characters to hold it all together, but there is a fundamental difference. When I first saw Crash I thought it was a funny, entertaining film with some light drama - later on I realised people were taking it as a serious treatise on the subject of racism and it's impossible to take the film seriously at all on that level. This film, thankfully has no such pretensions - it deals with life and death but it's not claiming to be anything more than it is and that's a refreshing thing.
At times this film is very funny, on occasion it is extremely touching and throughout the whole thing is extremely heartfelt. This is why the coincidence factor can be excused because usually coincidence is a cynical writing tool but this is a story so devoid of cynicism it balances everything out. This is by no means a perfect film, but Klapisch has given us a slice of life in the capital of his country straight from the heart, which most people would have a nice experience watching.