"Trainspotting" (1996)
Boyle, Hodge, producer Andrew Macdonald and McGregor swiftly got the band back together for another Edinburgh-set film that proved even more successful: "Trainspotting." Adapting Irvine Welsh's cult novel about heroin addicts, Boyle made a shocking, serious film, less attention-seeking than its source material, but crucially, also invested it with a rock n roll energy that, for a brief moment, made smack look like the most fun in the world (which, despite criticism at the time, is really the only honest way to go about things -- if drugs weren't initially a blast, people wouldn't do them). And among an exceptional cast, including early roles for Ewan Bremner, Jonny Lee Miller, Kevin McKidd and Kelly Macdonald, as well as an exceptional turn from Robert Carlyle as the psychotic Begbie, McGregor is electric as the lead. Boyle wanted a figure reminiscent of Michael Caine in "Alfie" and Malcolm McDowell in "A Clockwork Orange," and that's exactly what McGregor provided: with charisma to burn, he's at once repellent and hugely sympathetic. The film still stands as a high watermark in the careers of both star and director; they worked together one more time, on the messy-but-not-without-its-charms Coen Brothers-lite "A Life Less Ordinary," before falling out when Boyle cast Leonardo di Caprio as the lead in "The Beach."

"Velvet Goldmine" (1998)
From heroin addict as rock star to, well, plain old rock star, McGregor took a key supporting role in Todd Haynes' glam-rock "Citizen Kane," "Velvet Goldmine." McGregor channels Iggy Pop (and a little Kurt Cobain for good measure) as American rock star Curt Wild, whose affair with Bowie-esque legend Brian Slade is the centerpiece of the film, and he's pretty terrific. Sure, his American accent is as shaky as ever, but he makes a compelling Iggy-surrogate, full of the star's wild energy, but with a surprising vulnerability that you suspect you'd have to dig deep to find in the Stooges frontman. Oh, and he could really sing, something that the actor would return to in blockbuster manner later on. The film's plenty flawed, uneasily mirroring a crackerjack style with the director's intellectual interests,, but as ever, Haynes never takes the standard approach: what other rock n roll films begin with Oscar Wilde arriving in a spaceship? The cast, even the inconsistent likes of Jonathan Rhys-Myers and Eddie Izzard, are all great, the soundtrack is a hall-of-famer, and when it really works -- particularly in the seemingly autobiographical aspects of young journalist Arthur (Christian Bale), whose fan-to-journalist journey is far more moving than the similar path walked in "Almost Famous." Plus, it has a scene where Obi-Wan Kenobi fucks Batman through a shower of glitter. So it's got that going for it.

"Moulin Rouge!" (2001)
No one expected "Moulin Rouge!" to become the kind of phenomenon that it did. An operatic musical, shot in a hyperactive MTV style, using mash-ups of popular, anachronistic songs, from the guy who directed "Romeo & Juliet?" Really? But the film proved to be both a critical and commercial hit, prefiguring the revival of the genre, and picked up 8 Oscar nominations, including Best Picture, and landed on many "best of the decade lists" when the time came. While we're not convinced as to how well the film has dated, it remains an impressive feat and, while Nicole Kidman got most of the critical plaudits, McGregor's performance as romantic lead Christian is really what makes the film work. It's a tricky one to pull off, a combination of romantic naivety, seductive charm and some incredibly broad humor, but the actor manages it with aplomb; there are few actors that would have managed to play the part sincerely, without winking at the camera (and plenty of actors in the film do the latter), but McGregor has to play it straight, and smashes it. And his singing voice turned out to be genuinely impressive, particularly in his rendition of Elton John's "Your Song," paving the way to a starring role on stage in "Guys & Dolls."