Richard Belzer as John Munch
Georgia Engle as Mrs. Tottendale from The Drowsy Chaperone (you asked who I associated with a role)
Yul Brynner – the King of Siam
Cathy Rigby – Peter Pan
Don Adams – Maxwell Smart
Because I saw Star Wars when I was young, as far as I was concerned Mark Hamill was really Luke Skywalker. If I saw him in anything else, it was just Luke, and unfortunately I always thought Luke was a lousy actor - he should have stuck with his Jedi Knighting career.
But then I saw Jay and Silent Bob Strike Back. Now some sort of weird inversion has occurred, and when I watch any Star Wars movies, I can’t help but feel I’m watching Cocknocker playing Luke Skywalker.
So now, to me, Mark Hamill is Cocknocker Skywalker, and he always will be.
To be fair, that’s the only character he ever plays, no matter what show he’s on. 
To me, Billy will always be Fernando.
It might even be that there’s a paranoid detective named Munch impersonating a comedian named Belzer.
I really have a hard time watching old movies with Leslie Nielsen in them and taking him seriously. He’s Dr. Rumack or Frank Drebin, and always will be.
And yes, I’m serious.
Cathy Rigby will always make me think of Stayfree Maxi Pads.
He has put on some weight. But he’s in his 40’s now. But the Castle episode where he was trying on his space cowboy Halloween costume? He can still pull it off.
Yeah; my first thought upon seeing this thread was “Patrick Stewart = Captain Picard”.
To me, Marlon Brando will always be Don Corleone or Jor-El. And Robin Williams will always be Mork from Ork and Chevy Chase is Clark Griswold.
Giovanni Ribisi was on an episode of X Files where he used lightning to kill people. To this day, my wife and I refer to him as Lightning Boy.
Which is a real shame, since he’s a very well-respected theater actor.
“Lemme ask you something, Monk…would you fuck me? I’d fuck me. I’d fuck me so hard…”
Just about anyone from Animal House, and always by their nickname (Otter, Hoover, Pinto, Flounder etc.) Except for that one Omega played by the Footloose guy.
A few years ago, I would have said Ed O’Neill, but now I can watch Modern Family without thinking “Hey, it’s Al Bundy!”
Where do you guys stand on Pat Morita? Is he Mr. Miyagi? Arnold? Ah-Choo? (I’m in the Arnold camp)
I can’t believe no one has mentioned Hugo Weaving as Agent Smith (even if he’s Agent Smith in Rivendell, for instance).
My wife has been on a Grey’s Anatomy kick lately. I don’t much care for the show, but I amuse myself by asking her whenever Kevin McKidd comes on screen questions like, “Oh, so Vorenus is banging that Korean chick?” “What’s Vorenus going to do now?” and “He’s Vorenus, why doesn’t he just put them all to the sword?”
I completely agree with this one and want to add my own “I can’t believe no one has mentioned…” John Wayne, turns out every role he ever play was **Rooster Cogburn. **
Same with Titus Pullo on Dexter! 
The same here but only as Lt Buntz.
Maggie Smith = Miss Jean Brodie