Who in your opinion blew it the worst on their character's accent? For me it was David Ogden Steirs' non-Bostonian accent on MASH. I mean it was a repeated plot point that he was from Boston but the accent was nowhere near it.

Second-worst is Patrick Steward, the French captain with a perfect English accent. Hearing him introduce himself was always a "really?" moment.

Yours?

Gotta be Kevin Costner's English accent in Robin Hood, right?

There are a lot in movies (Sean Connery and Keanu Reeves come to mind), but this is in TV Talk.

Patrick Stewart is hardly an accent fail. He wasn't 'trying' to sound like he had a French accent. You might call it an inconsistency of the character, but it's not a fail.

Patrick Stewart as Professor X. Professor X is suppose to be American.

Amanda Tapping's accent as Helen Magnus in Sanctuary. It just sounds weird to me.

Ah. Missed that.

Morena Baccarin's Russian accent on The Endgame is pretty bad. Not nearly as good as Jodie Comer's on Killing Eve.

If we take the Star Trek universe at face value that everybody on Earth speaks English, we would also have to assume that this occurred due to the dominance of American culture.

Based on that, it seems far more likely that strong non-American accents like Scotty's would disappear in hundreds of years, rather than people from France still sounding like Pepe LePew.

Holy shit, whether in movies or TV shows, few things are as irksome as bad accents. I'd much rather the actor speak in his/her regular accent than some wretched imitation.

Everything I hated about “Chernobyl”

and refuse to acknowledge its praise

Gabrielle Anwar's Irish accent on Burn Notice. I think it didn't survive past the pilot.

I always thought it was really weird that they did not go back and re-record her dialogue in the pilot after she dropped the accent in the second episode.

First one that came to mind. Anwar claims the producers told her to drop it, because test audiences didn't like it.

Patrick Stewart wasn't trying to do a French accent when he was on TNG. This is Stewart trying to do an impression of a French accent:

Marina Sirtis initially doing a faux Israeli accent for Troi and a mossad character in NCIS, and a russian accent in Stargate SG1.

I love the movie, but Kevin Costner's Boston accent in Thirteen Days is worse than his English one in Robin Hood.

Sorry to hijack the thread because this is not a TV show nor even a movie, but one time I went to a local production of The Who's Tommy, and the actor playing the title character had the most over-the-top overly British accent of all time. He was more British-sounding than the guy who sang the role originally, who was ACTUALLY BRITISH! Like, I can't believe the director approved that. "Dude. Tone it down. Just sound as British as Roger Daltrey, ok? You know, from-Great Britain-Roger Daltrey?"

Mid-Atlantic Accent

Yeah, Winchester wasn't supposed to have a Boston accent. It was definitely a cross of the English and upper class American accent.
He did the accent well.

So the OP is 0/2 ?

Is that how Ogden Steirs actually speaks? The only other thing I recall ever seeing him do was the clock in Beauty and the Beast and it’s the same accent.

Indeed. It was much like that of Higgins on Magnum P.I. Not any British accent, not Bostonian or any specific New England accent, just an upper crust Mid Atlantic accent that represents arrogance and entitlement.

DOS was BRILLIANT as Winchester. I love the character. The show got infinitely better when he replaced Frank Burns (who, to be fair, was played brilliantly by Larry Linville, but he and the character got screwed - he played the only character in the cast who was not allowed to grow and become more human and less of a caricature, so he quit).

No, his real accent was somewhere in between Winchester and the Dad he played in Better Off Dead. The closest was probably his character on Stargate Atlantis.

Basically anyone not from Boston trying to sound like they are from Boston. Not literally everyone from the city sounds like the "your cousin, from Boston" guy. See: most actors from Departed and The Town.

Not at all. He appeared on an episode of Frasier (which was hilarious) and spoke in a normal accent.