Armstrong was a rising star when his cycling career was halted by advanced testicular cancer. With only a 50 percent chance of survival, he went through radical treatment and survived, then returned to sport with much more effective form. But he was also secretly involved in an extensive doping programme, rationalised by the fact that everyone else in cycling was doing it too. After winning the Tour de France seven times 1999-2005, he staged a comeback in 2009, reigniting old rivalries that resulted in the exposure of his drug use.

With an astounding level of access, Gibney shot a lot of beautiful footage in 2009, and he's clearly reluctant not to use it here. But centring the film on that race, which Armstrong continually claims to be racing cleanly, puts the emphasis in the wrong place. We would like more insight into the whole shady situation, mainly because Armstrong and others have always claimed that the field was even back in those doping days since everyone was up to it.

But this clearly isn't true, as some cyclists here talk about how they have always been the lone voice in the wilderness, struggling against competitors who had seemingly superhuman strength, while the culture of omerta (a code of honour) meant that no one was willing to spill the beans. Until the floodgates opened, that is. Oddly, even though Gibney includes interview footage shot before, during and after Oprah's well-reported confrontation, we don't learn much new from this film.

What intriguing to see is how elaborate the deception was over such a long time. But then we've never really trusted professional athletes to compete without some sort of high-tech advantage, whether or not it's officially banned. And if this film proves anything, it's that there's so much money to make in these sports that competitors will continue to cross the line if they think they can get away with it.

Born in Scotland, White studied in Paris and worked in New York before landing in the theatre business in London. As an independent producer, he took unexpected risks that paid off in the case of plays (Oh! Calcutta! and The Rocky Horror Show), films (Monty Python and the Holy Grail and White Mischief), and TV shows (The Comic Strip Presents, which launched the likes of Jennifer Saunders, Dawn French and Rik Mayall). In the process, he smashed the stuffy art scene. He also indulged in so much drugs, alcohol and partying that he's physically shattered today. Not that he'd admit it.

Assembled with energy and affection, this documentary is packed with beautifully animated snapshots from White's personal collection, showing his enduring friendship with some of the world's biggest celebrities. Several turn up to talk about his pivotal role in their careers, but the main thing they reveal is his friendship. Even after two strokes and serious heart surgery, White still likes to party into the night with the movers and shakers of the arts world.

Filmmaker Otto is clearly entranced by White's ultimate showbiz lifestyle, so she packs the movie with a blinding array of archive photos and film footage, plus interviewees who know White well, including his exes and two children. This gives the film a snappy tone with a wide variety of voices, cutting beneath the surface to explore both personal emotions and the wider effect White has had throughout the entertainment world.

Along the way, a clear theme emerges: that producers are no longer taking risks like White did. Sure, many of his projects were initially failures that went on to cult success, which didn't usually make him much money, but these kinds of films and plays simply aren't being made by today's corporate-minded producers. So White's endless optimism is inspiring, as are his two secrets to eternal youth: avoid complacence and stability, and surround yourself with young people.

In August 2008, 11 people died on the perilous slopes of K2 in 48 hours. K2 claims most of its lives on the descent, and indeed 18 of 24 climbers reached the summit on that fateful day. But a series of mistakes and natural occurrences combined to make this one of the most deadly days in mountaineering history. And at the heart of the mystery of what happened is the story of Irish climber Ger McDonnell, whose partner Annie, brother JJ and brother-in-law Damien set out to get the full story from Sherpa Pemba.

But by locking into a tight focus on Ger, the fulm begins to lose its documentary objectivity, becoming more of an effort to build Irish pride than to get at the truth. Much more telling are the comments from the survivors of that fateful day, but Ryan doesn't seem interested in them unless they support his thesis. He also makes the odd decision to cut away every time the story reaches a climax, giving background details and chronicling key 1954 and 2006 ascents.

The film looks amazing, as Ryan mixes archive photos and film with reconstruction scenes featuring the gorgeous cinematography of Robbie Ryan and Stephen O'Reilly. These are combined in a way that's eerily seamless, putting us right on the mountain with the actual climbers. And as the film chronicles each person's death, it feels almost like a Final Destination-style thriller. But since it's real, it's also deeply moving.

The fact that K2 claims the life of one in every four people who reach the summit is pretty horrifying. But a straightforward narrative docwould have been much more involving without all of the sideroads. But Ryan also jumps around the story itself in an attempt to generate emotion, which does the opposite. We just get frustrated that we can't follow the events properly. And in the end, his work to recast Ger as a hero (even if this is probably correct) feel pushy.

At the beginning of the 20th century, there were adults and children, but nothing in between. Then child labour laws gave children a sense of youthful freedom, which was rocked by two world wars and the depression, as well as the rebellious attitude of swing music. After all of this, young people were too independent to be treated as children again, needing their own sense of independence while still living under their parents' roof. And the New York Times essentially created the monster, printing A Teen-age Bill of Rights in 1945.

Filmmaker Wolf takes an original approach to the documentary form, creating what looks like a collection of wonderful archival clips. But very early on there's a sneaking suspicion that he's inserting fake footage in with the real thing. Indeed, entire characters are pure invention to show an aspect of the teenage experience, including a member of the Hitler Youth, a wild-living British socialite and a young black American.

The film is narrated with a variety of first-person voices as we meet these three characters and others. Each one catches our attention because there are aspects of their lives that we can identify with. They also offer clever variations on adolescent experiences in different times and places. Although there's nothing revelatory here, as teenagers have been rebelling against the world since the dawn of time.

The problem is that Wolf never finds anything that shows how the concept of the "teenager" is something new to the 20th century. He essentially proves the opposite: that struggling to make yourself heard between childhood and adulthood is a common experience throughout human history. And then at the very end, he stumbles onto something interesting: that post-war teens started fighting back against the grown-ups who had sent them to war, sparking the 1960s liberation, anti-Vietnam protests and even Tienanmen Square. Now that's an idea worth exploring.