The Weekend's Television: The Fallen, Sat BBC2 Outnumbered, Sat, BBC1

I had just finished watching Morgan Matthews's extraordinary film The Fallen when its opening title became obsolete. "To date," it read, "a total of 298 men and women have died whilst serving with the British armed forces in [Iraq and Afghanistan]". An hour later, the news reported that two Royal Marines had been killed in an explosion in Helmand province last Wednesday, and the total ticked up to 300 deaths.

Given the scrupulous inclusiveness of Matthews's project, I'm sure those two names will have been added to its catalogue of loss by the time of transmission. But it had already acknowledged that its tally of the dead would one day be incomplete with a telling final sequence. To the chinking peck of a chisel on stone, the camera moved around a war memorial where a mason was adding another name to the list. The last thing you saw was an expanse of empty space waiting for casualties yet to come.

The purpose of Matthews's film was to amplify the muffled impact of the news-in-brief headlines military deaths in Iraq and Afghanistan tend to be consigned to, reminding us that every fatal shot or explosion is followed by a secondary blast at home, leaving other lives shattered. The procedure of the film was simple: a chronological list of the dead ticking away through its three-hour running time, interleaved with interviews and memories and war stories of the bereaved, about how they first heard, about their last goodbyes and about what it feels like when you first see the transport aircraft that's carrying your son back to Britain in a box.

It presented grief as both universal and utterly individual. The parents of Lieutenant Alexander Tweedie had been schooled by tradition and history to keep a stiff upper lip. "He would have regarded any obvious grief as sentimental, I think," said his father. "Perhaps we make too much of casualties now... there is a validity to that point of view." And yet, describing his son's funeral service, his stoicism faltered and broke, as wrenching as only unsuccessfully suppressed emotion can be. Again and again, it wasn't people crying that made you tear up watching this film. It was seeing people try not to cry and failing.

There was a desperate poignancy to the shrines people had constructed, too, clinging on to the relics of a child's life and insisting on their continued presence. "Your hope is that he's going to come back through that door one more time," said one mother, showing Matthews her son's bedroom, with his Sex God tie, and his Charlton Athletic wallpaper, and the shirt he'd worn for his last day at school, scrawled with joky obscenities, and good-luck messages, and the sadly inaccurate message, "I'm sure you won't really get killed". Sometimes, the forms that commemoration took were startling. More than one parent had settled on a portrait tattoo of their dead child. Another family had turned their house into a kind of melancholy souvenir shop: "We've got Michael on cups, place-mats, fridge magnets... we've got him on key-rings." They also had him, the camera revealed, on a kitchen clock, etched into glass for the conservatory roof, and printed on to a heat-sensitive mug, so that his face appeared when hot liquid was poured into it, although this last item hadn't lasted. "I found that quite hard because it was like he was gone and then he was back and then he was gone, which I found quite gruelling to have in the house," his mother said. Last rites had been almost as idiosyncratically variable, from formal military funerals to the dispersal of the ashes by means of a firework display.

Given the hazards of this subject matter – the traps of sentimentality and easy tear-jerking that it might have sprung – the film almost never put a foot wrong. There was a moment when a young girl was filmed at her brother's grave that felt awkward and uncomfortable, as if a distress had been procured for the camera, and I couldn't help but wonder how painful it might feel to see your son or daughter pass as one of the many deaths commemorated only by a name, glowing briefly gold against the dark before giving way to the next casualty. But such doubts barely counted against the tact and humanity and, yes, even the sorrowing humour of the thing. I'd be astonished if we see a more moving film this year, or next.

No room to properly do justice to the brilliance of Outnumbered, which has deservedly been promoted to a prime Saturday slot. But I would like to share the theological conundrums a hapless vicar found himself faced with after unwisely crouching down to talk to a group of children at a wedding: "Why has God only given us 15 thousand billion years left to live before the sun dies?" and, trickier still perhaps, "What would Jesus do if he was attacked by a polar bear?"