Matteo Garrone's Gomorrah is a messy, sprawling and often devastating insight into the operation of the underworld organisation Camorra in the rundown tenements of Naples. The speed and complexity of this adaptation of Roberto Saviano's bestseller is mesmerising. But the film's power and compulsion comes from the deft way in which Garrone gets into the corrupted souls of the principal characters — young Salvatore Abruzzese who sells out the woman whose shopping he used to collect after becoming a bag handler for a drugs baron; reckless teenagers Marco Macor and Ciro Petrone, who steal guns belonging to complacent hood Carlo del Sorbo and try to move on to his patch; ageing tailor Salvatore Cantalupo, whose desire to make it in haute couture lures him into a dangerous deal with a Chinese sweatshop; shady businessman Toni Servillo who tutors novice Carmine Paternoster in the sinister art of dumping toxic waste; and 'submarine' Gianfelice Imparato, who tries to help debtor families manage their pay.

With the authenticity of the action being reinforced by both Marco Onorato's gritty images of the Casal di Principe district and the insular argot of the Neapolitan dialect, this is a masterly depiction of the Camorra footsoldier and the poverty, despair, fear and twisted sense of loyalty on which he thrives.

Inspired by Pavel Tetersky and Sergei Sakin's prize-winning memoir, Bigga Than Ben: The Russians' Guide to Ripping Off London! bristles with attitude and energy as it follows Andrei Chadov and Ben Barnes around the capital in pursuit of a quick buck. Tutored by shady Mr Fixit Ovidiu Matesan and his sidekick Hero Fiennes-Tiffin in the fine arts of shoplifting, ripping off banks, joyriding on public transport and selling knockED-off phones, the pair soon find themselves descending into an underworld of drug dealers, exploitative bosses and rackrenting landlords. So, when the homesick Chadov succumbs to addiction, Barnes decides to take control of his miserable existence.

Director S. A. Halewood definitely captures something of the dangerous dinginess of London's lawless backstreets. But his crash-bang approach owes far too much to early Guy Ritchie and the pre-eminence of style over content ultimately undermines the authenticity of the savage story.

In addition to writing, directing and producing, Marianna Palka also stars in the resolutely offbeat indie, Good Dick, in which a loner with a penchant for softcore porn finds an unlikely soulmate in the geek from the local video store. There's something sinister about the way in which Jason Ritter inveigles his way into Palka's closely guarded existence, whether he's playing on her insecurities to gain her confidence, sleeping in his car outside her apartment block or watching her masturbate through a window. But even though Ritter worms his way into her bed, Palka seems to be in control of the situation, most notably when he boasts that he's better endowed than the star of the latest smutfest they're watching. However, her fragility is disturbingly exposed in a showdown with abusive father Tom Arnold and the denouement suggests she's invested her trust in another unreliable creep rather than found lasting love.

Following eight high-schoolers from across the US, Adam Yauch's account of the inaugural Elite 24 basketball game, Gunnin' For That #1 Spot, concentrates as much on sponsorship deals as hopes of playing in the NBA. Lacking the intimacy and insight of Hoop Dreams, it fails fully to indict the corporations who prey upon the wannabes and rob them of any real enjoyment, as they play to catch the eye rather than as part of a team. Moreover, by presenting only a snapshot of each kid, Yauch treats them as disposably as the suits seeking to groom them for cynical stardom.

The big game is archly shot and edited, suggesting that the director is keener to showcase his own artistry than the athleticism of his subjects. Yet, for all its fish-eye, slo-mo casuistry, the showdown on the famous Rucker court in Harlem confirms that street basketball is as much about sporting as sport.

As one might expect of a film directed by a Beastie Boy, Gunnin' hasa high-octane hip-hop soundtrack, and the music is also one of the strong points of Jerry Rothwell's Heavy Load, which follows an eponymous punk band from its origins in backstreet Brighton to the Wychwood Festival and on to a media crusade to change care practices for adults with learning disabilities that even attracts the support of Kylie Minogue.

The action is dominated by Michael, the Down Syndrome drummer who becomes convinced he's the band's driving musical force and the star of the movie. But while his Spinal Tap-like tantrums form the core of this delightful odyssey, Rothwell also includes sympathetic profiles of Simon the wild singer and Jimmy the methodical guitarist, as well as support workers Mick and Paul, who strive selflessly to keep the group together. Indeed, as things get tough, the director even finds time to question his own motives for making the film, as he realises that his desire to feed off the combo's excitement and enjoyment is sapping its energy and enthusiasm.