Ritchie Coster by any chance?
I’m not sure he meets the criteria of the thread, then—if he always played a cop, then surely he must have been typecast for everyone, not just for you…?
Nick Chinlund? https://www.imdb.com/name/nm0157915/
I think Rowan Atkinson has avoided being typecast in my head because he has had two standout but very different roles in his career: the aforementioned Mr Bean, but also Blackadder (albeit the latter with differences each series).
The very first thing I ever saw Mark Ruffalo in was the underappreciated You Can Count On Me, where he played Laura Linney’s kinda ne’er do well brother, Terry.
He’s carved out a nice career, and I really enjoyed his Bruce Banner in the Marvel projects.
But he’ll always be Terry to me.
Sean Penn will always be Spicoli from Fast Times at Ridgemount High
My game (or maybe my way to be annoying) is that when someone is the “killer of the week” on a show like Monk or Criminal Minds they are branded as a murderer (if I remember who they are). If they show up in a different show then I call out “murderer” when they are on the screen.
So Norm Wendt is a murder on a Columbo episode and gets called a murderer every time we watch Cheers.
His name is Tim Guinee. He’s got a very “sensitive guy” look and soft voice, so he takes you by surprise when he turns out to be a particularly cruel mass murderer/stalker/serial killer. Yes, he is both a mass murderer and a serial killer-- and a child murderer. He also gets a “not guilty” by taking the jury foreman out to dinner, and convincing her that they are soulmates– and you believe he could do it.
And his cruelty doesn’t even end there.
The murderers who look like murderers on L&O don’t creep me out, because I’d cross the street if I saw them coming and there weren’t a lot of people around, but this is the kind of guy who, if he sat next to me on a subway or a plane, and said something to me, I’d probably start talking to him without even really thinking about it.
If he were model-attractive, or banker-slick, I’d notice, but he’s more ordinary. And it’s so creepy to watch happen to someone else, especially realizing that if it happened to ME, I might not even notice.
David Anders is Sark from Alias. Every time we see him, one of us mentions Sark.
Whatever character Melissa George is playing is not to be trusted, due to her role as Lauren Reed, also from Alias.
This is exactly why I find Anthony Perkins as Norman Bates in Psycho to be so disturbing,
Same for me. Great film BTW. That scene towards the beginning at the restaurant as he reunited with his sister had me squirming in sympathy as he was trying to explain himself to her.
Jeremy Allen White will always and forever be Lip Gallagher from Shameless.
He’s not a chef (The Bear), and he certainly isn’t Bruce Springsteen (Deliver Me From Nowhere), although I thought he did a fine job in that movie.
He was also one of the villain’s victims in The Hidden, not even an authority figure but a hospital patient whose job is never specified. On the other hand, Kyle MacLachlan plays an FBI agent (three years before Twin Peaks).
Quasi-related to this topic, I first heard of Danny Elfman as the voice of Jack Skellington in The Nightmare before Christmas, and it took me a bit to move him from the mental category of “voice actor” to “composer”.
Since I didn’t care for my brief exposure to Mr. Bean, I watched very little of it. But I loved Blackadder (minus the one-offs), so Rowan Atkinson is only and always Blackadder 
.
I remember that episode. I thought it was Nathan Fillion in that role for a while, then found out it wasn’t. Guinee was in one of the Iron Man movies, wasn’t he?
Ritchie Coster is the killer on L&O that was so creepy his public defender was freaked out to be in the same room with him. Then his second lawyer goes to look at some dead bodies the client tells him about and winds up getting convicted as an accomplice to murder.
He shows up in a couple more episodes in the Law-and-Orderverse; once as a rather effete orchestra conductor, I think. I knew I recognized him from somewhere, but took a while to make the connection.
My favorite movie is The Right Stuff. Levon Helm plays Yeager’s engineer, Jack Ridley; clean cut, short hair. When I saw a clip from The Last Waltz with him singing “The Night They Drove Old Dixie Down” I barely recognized him. Next time I saw the movie I noticed how he twirled a piece of broomstick on his fingers; a skill I’m sure he honed with drumsticks.
LOL that reminds me of an episode of Criminal Minds my wife was watching a while back, where the serial killer of the week was Brian Baumgartner, aka Kevin from The Office. I’m sorry, but I just couldn’t take him seriously as the SKotW after all those years of Kevin. He’s not that smart!
Whereas, I originally knew of Danny Elfman as the vocalist and co-leader of the '80s rock band Oingo Boingo, in particular their songs Dead Man’s Party and Weird Science. When he started writing film scores – especially the 1989 Batman film – I kept thinking of him as “that Oingo Boingo guy,” and it took me a while to think of him otherwise.
And of course Captain Blackadder of “Blackadder Goes Forth” famously hated another mostly-silent film actor….
Please please please.
For me, Ron ruined Band of Brothers. I kept expecting him to complain about TPS reports and Flair. But now that I think about it, Nixon was a little bit like Peter.