Not a voiceover, but I still found it hilarious. A couple decades ago, I was watching an airing of History of the World Part I on a UHF channel. They chose to bleep the profanity. Amusingly, they did a terrible job of it.
When Bea Arthur is repeatedly using the word “bullshit” in her conversation with Mel Brooks, the audio bleeped out the syllable “bull” and left “shit” intact and distinctly audible. There were other examples later in the film, but I’m not recalling them now.
One of the worst I can remember is during Blazing Saddles. Gene Wilder is describing his lowest point as a gunfighter when he confronted a ten year old boy holding a gun on him.
Wilder says he turned away in disgust and then “…the little bastard shot me in the ass!” On TV, the line is dubbed “…the little brat shot me in the…you know…”
It’s the absolute worst dubbing I’ve ever seen. Wilder bellowed the word ‘ass’, so his mouth is onscreen wide open and unmoving while there’s a pause on the sound track and the words ‘you know’ come out in a muffled mumble. The cheapest sync job on a seventies kung fu movie was never so unmatched between words and mouth movement.
I think the most nonsensical translation of profanity I can think of was on a movie called DC Cab. There’s an argument among cabbies going on, and someone yells, “If we need anymore shit, we’ll squeeze your heads!” This was switched to “If we need anymore stuff, we’ll squeeze your heads!” As an insult, even as a coherent statement, that doesn’t make any sense.
One of my favorites that I saw many years ago was the original Police Academy. The evil Dean of the academy (or whatever) says, in the original,“Nobody fucks with me!”. In the TV version he says “Nobody” then there is a long pause and then a completely different voice with a completely different inflection and volume says “PLAAAAYS” another pause, “with me.”
Just rehearing it it in my head makes me laugh and laugh!
The first time I saw The Breakfast Club, it was on network TV at the tail end of the eighties, when standards were tighter in ways which would probably be incomprehensible to younger people.
One of the bits of re-looped dialogue that stood out was Judd Nelson’s bad-boy character telling a teacher, “Eat my socks.” Naturally I decoded this as “Eat my shit” – I was stunned a few years later when I watched the unedited version and learned that the too-hot-for-network-TV line was actually “Eat my shorts,” which of course in 1990 became one of the most recognizable TV catchphrases of all time. D’oh!
Wow. Shit, piss, fuck, cunt, cocksucker, motherfucker, tits…
And shorts?
How about Die Hard with a Vengeance: “melonsucker” substituted in.
Sticks out like a melonfarmer, don’t it?
Tremors.
They finally kill one of the Graboids, and Kevin Bacon runs up to it, shaking with rage, points his finger at it, and with spittle flying everywhere, screams, “CURSE YOU!”
The edit for ABC Family goes further. Someone took the first “horses” from “Horses? We can’t afford to lose no horses.” and used it to overdub the “faggots” in “Kansas City faggots!” I didn’t bother to see what else they did after that.
Another one from Police Acadamy (the original) when they were learning how to “use their voices with authority” the real line Tackleberry yells “Drop that stereo before I blow your goddamn nuts off asshole” turned into “Drop that stereo before I blow your gosh darn knees off eggroll”
And the classic Die Hard 2 example:
Yippy Kay yay Mister Falcon
What’s really amusing these days is the Inspiration Channel is bleeping out the word ‘damn’ from Little House on the Prairie. They’re censoring Little House on the Prairie for chrissake!
Don’t you mean “They’re censoring Little House on the Prairie for cryin’ out loud”?
The entire scene with the Penguin changes. She is whacking them with the ruler, and each time they curse. Except they don’t curse with dubbing. Which makes the scene all the more confusing (and funny if you know what is supposed to be going on).
I was hoping someone would catch that. 
Something that bothered me about the uncut version of that scene: Why did they have Charles Durning do that voice-over!?
I opened this to post that one. Gleason didn’t even say “son of a bitch”, he said “sum-bitch!” with an exaggerated southern drawl. Worse still, they had fucking Fred Flintstone (Henry Corden) dub it.
I’ve said this before, the worst dubbing they do to Blazing Saddles is that they replace every occurrence of the word nigger with-
Absolutely nothing! They just mute it!
Doing that actually changes the whole context from comedy*** to*** racism (precisely 100% the opposite of what they think it does!!)
Some movie - possibly Quick Change - saw a character o from being a “fucking motherfucker” to a “Viking melon farmer.”
In Fargo, they replace “fucking” with “frozen”, which y’know, goes with the setting.
I don’t know if it’s better or worse when they just substitute silence for the no-no words. We were watching Jesse Stone on (I think) the Hallmark channel, and there were obvious gaps in some of the lines. Since I was knitting, my eyes were less on the TV and I was listening more than watching, so it really stood out.
So silly…
My favorite was Lethal Weapon on broadcast TV:
Muffler Suckers.
Man, I use that all the time now. “I’m nodding off like a muffler sucker”.
There’s an episode of All in the Family where Mike’s buddy stops in during the holidays. He’s a draft dodger who is just coming back from Canada. One of Archie’s friends, who lost a son in Vietnam Nam, is also invited to the holiday meal. Everything blows up at dinner. There’s a powerful moment where Archie yells at the young man and says something to the effect of “that g-ddamn war.” The first time I saw it on either Nick at Nite or TVLand, it was unedited. But then when I saw it again about a year later, it was edited to “rotten damn.” Completely ruins a moment in a tv show that was originally aired at least 35 years before.