In 2014, filmmaker Fogel decides to see if taking the same kind of steroids as Lance Armstrong will have an effect on his performance in the Haute Route, a fierce amateur European bicycle road race. He seeks out American doping expert Dan Catlin, who's uneasy with this so refers him to Russian expert Grigory Rodchenkov, an official with the World Anti-Doping Agency. And Grigory turns out to be quite the character, advising Fogel by Skype before visiting Los Angeles so he can smuggle urine samples back to his Moscow lab. Then the global doping scandal erupts around him.

The film's breakneck pace is gripping, especially as things turn seriously nasty. The opening sequence is played for laughs, Morgan Spurlock-style, as Fogel injects himself with hormones and participates in the race (he finishes in a lower position, which intriguingly disproves the point). At the same time, the Russian doping scandal is gaining traction, with Rodchenkov at the epicentre. So he goes on the run. And Fogel transforms the film into a thriller with fast-paced editing and a tension-building score.

The suspense may be overwrought, but Rodchenkov's revelations are genuinely shocking. And he's a terrific movie character: a cheerful, witty, life-loving guy who understands the irony of being an anti-doping official who is also the mastermind of the biggest ever drug scandal. His favourite book is Orwell's 1984, and he readily identifies with the idea of "doublespeak". His detailed explanation of the elaborate operation at the Sochi 2014 Winter Olympics would sound absurd if it weren't true.

Basically, the film is saying that most competitors in most sports are involved in some kind of dodgy performance-enhancement, violating the rules whenever they can get away with it. Fogel never gets around to asking the bigger question about whether there needs to be a rethink to the approach to this issue, or if there's an answer to the huge questions raised by these revelations. But he does make sure he keeps the film both entertaining and chilling right to the very end.

In mid-70s Melbourne, Tim and John Caleo first met as 14-year-old classmates. A theatre nerd and a footballer, their friendship was unlikely, but it soon blossomed into romance. Tim's parents were shocked when he came out to them, while John's parents threatened legal action against Tim. Under these and other pressures, they took a break in their relationship. Tim moved to Sydney to study acting, and John followed later, rekindling their relationship. Tim's 1985 play Soft Targets was one of the first projects to address the outbreak of Aids. That same year, both tested positive for HIV.

The film is narrated by Conigrave himself through extensive audiotapes, then illustrated with home movies, snapshots and re-enactments. Added to this are interviews with friends who offer first-hand reminiscences. Their anecdotes are remarkably personal, especially as they struggle with emotions while describing the advance of Aids-related illnesses for first John, then Tim. This creates an unusually vivid portrait of both men's personalities and their relationship. And it fills in the story with observations from friends. Family members participated in the film, but oddly don't appear in interviews.

Without overstating it, this is a lovely exploration of how the 1970s offered hope for the future and a freedom for teens to decide how they would live. But of course this is followed by a fight for equal rights and the devastation of Aids. But the filmmakers keep everything strikingly specific, offering an important angle on how these issues have affected people and society. Tim was at the centre of the activism, and his writings reflect his personal thoughts and experiences. After John's death, he wrote Holding the Man to recount his own tragic love story only shortly before he died.

This film beautifully recounts Tim's life. Sometimes, the filmmakers seem to milk the wrenching emotions, cranking them to almost unbearable levels with photos, music and editing choices. But then, this is an unusually evocative story, and by telling it with such an attention to detail, the film becomes a vitally important document about both an astonishing period in human history and one beautifully unremarkable couple.

In the wake of Chelsea Manning's leaked documents in 2010, Assange lost his anonymity for good. Holed up in the English countryside, he continued working to release leaked documents with his editor Sarah Harrison, as expert Jacob Appelbaum continues the work in other countries. Meanwhile in Sweden, two women filed complaints against him for sexual assault (charges were never filed). Fearing that he might be extradited from Sweden to the USA, he applied for asylum in the Ecuadorian embassy in London, where he has remained since June 2012.

Unlike Citizenfour, in which Edward Snowden is clearly acting in the best interests of the American public, this film never portrays Assange as any kind of hero. Poitras spends a lot of time with him over a number of years, showing him operating to his own secretive agenda. There's a clear sense of integrity to his actions, including a desire to protect his people and to make sure that any material released doesn't jeopardise anyone's life, and yet he has been used by others to release compromising material (such as the Democratic email leak in the summer of 2016).

Most interesting is Poitras' decision to edit the film out of sequence, jumping forward and backward in time. This is most noticeable in Assange's continually shifting haircuts, and it builds to a thriller sequence when he dyes his hair and beard to elude the police as he goes into hiding at the Ecuadorian embassy. Poitras crafts this into an intriguing look at the standoff between a global superpower and a whistleblower who threatens them simply by revealing the truth.

Along the way, there are several surprising twists and turns, including an amusing visit from Lady Gaga, who halfheartedly interviews Assange in the embassy. And like a smear tactic from a political thriller, oddly similar sexual abuse accusations (again without charges) are levelled at Applebaum. Through all of this, Poitras asks the echoing questions in her voiceover narration, wondering about Assange's motives and what the situation means in the bigger picture. In other words, there are no answers here, but she raises important issues that seriously need to be addressed.

The film centres around footage from an unfinished documentary about Houston's 1999 world tour, her last triumph, during which her world began to unravel. A singing prodigy, Houston had been moulded by her mother, gospel singer Cissy, to become a crossover popstar. She met Bobby Brown in the late 1980s, and their relationship blossomed, even though he had severe clashes with her right-hand woman Robyn Crawford. Then Houston's casual drug use, which began in her childhood, grew unto full-on addiction. Combined with her crippling self-doubt, the problem became toxic.

Expertly edited, Broomfield structures this out of sequence, moving from past to present while circling back to the 1999 tour. Much of this footage is so intimate that it feels voyeuristic. Cameras capture Houston's lively backstage interaction with Crawford and Brown, including some startlingly private moments. And extensive performance clips offer insight while reminding us of her extraordinary gifts as a vocalist and entertainer. Scenes of her with a young Bobbi Kristina are haunting in retrospect.

Clips are included from Houston's iconic interviews throughout her career, starkly revealing the shift from a cheeky 19-year-old into an emaciated woman desperate to hold it together. The most glaring omissions are Crawford and Brown, who are present in archive footage. Both could shed light on various rumours, but they are understandably not talking. And of those who openly express their feelings, the most striking is bodyguard Roberts, whose comments seem oddly chilling. Indeed, he warned the family in 1995 what would happen if they carried on. And he was sacked for saying so.

Without Crawford and Brown on the record, questions remain at the end. Were Whitney and Robyn a couple? What really caused the demise of her marriage to Bobby? Why did no one seem to help Bobbi Kristina? There are plenty of hints, but no facts. Instead, the film focusses on Houston's trajectory as a bright star who was never allowed to be herself, a woman in search of unconditional love who, when she couldn't find it, dulled her senses with drink and drugs. It's a desperately sad story, and there's more to it than this.