Everyone has a favourite Robin Williams film; from the silly Mrs. Doubtfire to the serious Dead Poets Society to the sentimental Aladdin, much has been said about his greatest hits since his untimely passing earlier this month. Williams, however, had far more than just a handful of beloved films under his belt, having appeared in nearly 70 films over 37 years (nearly two a year) in a long-but-not-necessarily-always-illustrious career.

Let’s not kid ourselves: Robin Williams made bad movies too. For every Good Will Hunting or Good Morning, Vietnam on his filmography, there are such famous bombs as Popeye or Jack. In fact, the later years of his career saw Williams stuck in generic, throwaway roles that were bordering on parodical, pale imitations of his comic greatness. Yet for every Old Dogs and Licence to Wed he made, Williams also starred in darker, underrated gems that have been mostly overlooked in the past few weeks. Granted, these films aren’t always the easiest to watch, perhaps more so now than ever, but Williams was far more than a Top Five list of films which were made early in his career. If anything, his later work demonstrates a maturity and desire to break free of the mould he created and wore so well. Much like a clown given up on making us laugh but still bent on our attention, he tackled these roles with the fervour, alertness and wit of a stand-up comic, albeit with none of the comedy. And the end results are some of the finest performances of his career.

In 2002’s One Hour Photo, Williams played a timid photo kiosk clerk who becomes obsessed with the family whose photos he’s been developing. It’s perhaps his most subdued and engrossing performance, and one of the most chilling portrayals of obsession ever committed to screen – partially thanks to Mark Romanek’s clinical, almost Kubrickian direction. While many a comedian would have gone the deranged loony route (think Jim Carrey in The Cable Guy), Williams instead brought to life a soft-spoken introvert that was so effective in particular because it was such a far cry from his normal on-screen persona.

In the same year, Williams also went dark in director Christopher Nolan’s Insomnia. A remake of a Norwegian thriller, Insomnia was only the third film from the now-revered Nolan, known for his originality and risk-taking, particularly where casting is concerned (Heath Ledger as the Joker, anyone?). As such, the film’s highlight is undeniably Williams as a crime writer suspected in the death of a teenage girl. He more than stood his ground opposite the likes of Al Pacino and Hilary Swank, delivering another unsettling and eerily static performance.

Perhaps the best example of Williams’ dark side, however, can be found in the criminally underseen World’s Greatest Dad. In it, he treads similarly dark waters as a dismal father who, upon discovering his teenage son dead from autoerotic asphyxiation, pens a phony suicide note to avoid having to deal with the consequences of his poor parenting. A risky venture that cleverly explores our perverse desire for infamy, the film is powerful and was a critical success, but its dark subject matter meant it never quite found an audience.

Perhaps what made Williams excel at his dark roles was that they showed a side of him no one else had seen: anything but the manic energy and irrepressible improvisations that made him a household name. Whether or not this side of him was closer to his off-screen persona, we’ll never really know. But perhaps there’s solace to be found in the thought that even just for a while, Williams got to be himself. Vale, Robin.