Both Chris Hemsworth and Chris Pine are generally marketed as leading men, but both seem to have pretty decent comedic chops as well. Are there any other actors who you feel could do more than they’ve been offered? I’m also thinking of Robin Williams as a surprisingly scary villain.
Robin Williams doesn’t really have much more opportunity–he passed away, in 2014.
I think David Tennant could do more “mainstream” work and be more successful at it–he’s found a niche in SciFi and Shakespeare. Same with Patrick Stewart.
Tripler
Guess who just watched Hamlet. Go on. . . take a guess.
Robin Williams was a good villain in Insomnia and One Hour Photo.
Oh he definitely was-I worded it badly in my OP. I am also aware he’s dead. 
I think you haven’t seen a lot of David Tennant’s work. He has done quite a lot of mainstream dramas as well as what you mentioned. He also does a lot of voiceover work. His career is pretty diverse.
Jensen Ackles would be a good comedic actor, judging by the comedy episodes they’ve done on Supernatural.
Admittedly, I havent! I don’t get out much. . . What would you recommend?
Tripler
I’ve got access to a decent library system with diverse titles.
Yep. He’d also do well playing an assassin or killer, I think.
Pre- Doctor Who he first became known with his starring role in Casanova.
In recent years he starred in Broadchurch which is a crime drama. Season 1 was excellent, season 2 I disliked and season 3 was just ok. But David Tennant was fantastic all the way through. He also starred in the American remake which I didn’t see (Gracepoint).
His episode of Criminal:UK was also very good.
It is a genre piece but he was great in Jessica Jones even though it’s a superhero show he is more of a psychological villain. Probably the best villain role in any superhero franchise.
Robert Patrick, who played the T-1000 in Terminator 2 and a succession of other tough guys, knocked it out of the park when he wound up cast as a Jerry Lundegaard-esque hapless schmuck in The Sopranos. That guy has some serious acting chops because he portrayed a pathetic, can’t-catch-a-break uber-loser so well you forget he was even acting.
Also recommended if you can find it: Secret Smile, a two-part television drama (originally on ITV in the UK, and later on BBC America). Tennant is seriously creepy.
Also, if you haven’t yet seen Staged with Tennant and Michael Sheen, you really, really need to.
Easy top five, I’ll grant you. 
Always wanted to see Jack Klugman play some raging, homicidal psychopath who turtures and dismembers and disembowels his victims, but was denied of this wish and had to settle, instead, with Robert Reed branching out in “The Secret Night Caller”.
Still dealing with Tony Curtis as the “Boston Strangler”, and the odd way the film ended.
ETA: Gary Busey has been overdue for a little career re-vamping…maybe a quick haircut and maxillofacial surgery, he should be good to go for something maybe not quite his metier, like some light rom-com where he leads alongside, say, J-Lo or Lady Gaga (or Mila Kunis?)
Thanks guys! I’ll check them out!
Tripler
Now if I can just get a weekend off to relax. . .
In “Death to Smoochie”, Ed Norton played some happy-go-lucky shmuck in a mouse-like costume, and I figured if there was a sequel, and they couldn’t get Ed, then this would be the perfect branch out opportunity for either Tilda Swinton or a current Gerard Depardieu.
There’ve been several actors over the years who played a role where they had to appear to be a skilled musician though they weren’t, and pulled it off so well there was “they should be a musician fer realz!” buzz.
And of course there are many actors who also play music for real, at various levels of skill and dilettantism. My wife’s friend’s most prized possession is a sweat rag that Keanu Reeves threw into the crowd during a Dogstar show.
ETA: upon reskimming the thread, it appears the topic may be more narrowly defined as “actors who should branch out into more challenging acting roles” rather than, “actors who should branch out into other talents in real life”. If so, please ignore the above and carry on… 
He was also the voice of Scrooge McDuck in the recent DuckTales remake. It’s a very different kind of character.
I had a very low opinion of Adam Sandler until he branched out of juvenile comedy into things like Punch Drunk Love and Uncut Gems. Turns out the guy can act!
There was also a crop of pretty boy leading men like Brad Pitt and Leonardo DiCaprio who I hated until they got older and actually had to act instead stand there and smile.
DiCaprio went full retard right outta the chute in What’s Eating Gilbert Grape? and that was not by any means a “pretty boy” role. And Brad made plenty of challenging choices, playing villains in Thelma and Louise and Kalifornia. He was by no means willing to be typecast no matter how much Hollywood wanted him to be. I’d say they’re both excellent actors nearly hamstrung by their looks who were looking to diversify their portfolio from the get go.
I haven’t seen Kalifornia but Thelma and Louise was exactly what I hated about young Brad Pitt. A guy who win a woman with a goofy grin and then use her. Maybe leading man was the wrong choice of words. Anyway, I don’t think we disagree about much. Maybe it would be better to say that they are both excellent actors but I was unwilling to see it when they were young.