He's having quite the year.
And it's a measure of just how good he is performing at the moment that, unlike the Ryan Goslings of this world, each performance stands on its own merits - no repeating a formula here, no siree Bob.
There has been quite a buzz about Filth, and we've been giddy here at Popcorn Towers since seeing the full, filthy trailer recently (family-friendly version here, obviously, but the one you really want is on YouTube).
And the film does not disappoint.
Based on the Irvine Welsh novel of the same name (and, not having read it, I can't comment on the accuracy of the adaptation - but I'm guessing the phrase "based on" is key), Filth tells the story of bloated, bigoted, corrupt cop Bruce Robertson.
Bruce, played wonderfully by McAvoy, is not having a good time. It's Christmas, his wife seems to have left him (he's not sure if, or why, she has) and he's chasing a promotion at his Edinburgh cop shop.
Then there's a murder to solve. And an obscene caller to track down. A copper's work is never done.
And it's not easy work, especially when there's so much coke to snort, colleagues to discredit, booze to drink, women to shag, parties to organise and Masonic meetings to attend.
Bruce is a busy boy and no mistake.
He's also having a total meltdown as past events, current events and all that coke (not to mention the proper drugs he's prescribed) combine to bring his various mental walls crashing down.
This is, I think it's fair to say, not an easy film to watch.
It's gritty, dirty, visceral, surreal, nasty, violent, sexual, foul-mouthed and coked off its knockers.
Put more simply, it's great.
Part of me thinks it shouldn't be. The lead character is loathsome - and it's a mark of just how good McAvoy is that you find yourself liking him. Even when he's spiking his only friend's beer in a gay club in Germany.
Because, underneath it all, he has moments of genuine warmth and empathy. He's become this monster, but buried way underneath nice old Bruce is still lurking - even if it takes a total stranger (the delicately fragile Joanna Froggatt of Downton Abbey fame) to make him actually feel something.
Although how she manages to get through all that coke is a mystery. I've never touched the stuff and even my nose was tingling from about halfway through.
But for all the grit and filth and nastiness, there are some lighter moments and fun to be had. You will laugh. You will also squirm and feel sick - particularly when humble accountant Bladesey (Eddie Marsan in another great performance) is honking up in his hand after popping to see Bruce and having 'just the one'.
McAvoy's ability to switch from fear to anger to, well, any one of the myriad of emotions Bruce's crazy cranium throws up, is just wonderful to behold - he literally IS Filth - but he somehow manages to not steal any of the spotlight from the supporting cast.
Jim Broadbent as a mad Aussie doctor, John Sessions as his superior officer, Imogen Poots, Jamie Bell and Emun Elliott (yup, him from Threesome) as his colleagues, all put in stellar performances, balancing out the madness McAvoy's Bruce is immersed in.
And also, look out for David Soul, in one of the weirdest yet perfect cameo roles you'll see this year. Or any year.
As I've said, Filth is not a relaxing film to watch. It's enthralling, though, and you find yourself being dragged (and drugged) along for a smidge over 90 minutes without noticing.
It's as much a look at police corruption and abuse of power as it is a look at one man battling his many, many demons. It's a rollercoaster, a rude, sweary, sex-fuelled, coke-riddled, whiskey and beer-soaked rollercoaster, which takes no prisoners but does beat up and threaten a few.
You can't relax, and by the end you feel drained, but you'll have had fun. Sort of.
There will, of course, be some who will make obvious comparisons with Trainspotting (it's Scottish, written by Welsh and full of drugs), but that's unfair.
Filth deserves to stand (slumped against a wall looking as rough as a badger's bottom, granted) on its own.
Now, if you'll excuse me, having seen both Blue Jasmine AND Filth this week, I feel the need to check myself into a rehab clinic...