My FAVORITE type of bad dialog is as follows
-Heroes are surrounded by an angry mob of people
Mob Leader: -shouting- YOU BROKE INTO THE MAYORS HOUSE, BURNED DOWN HIS BEDROOM, STOLE ALL OF HIS VALUABLES AND GAVE HIM SUCH A SHOCK HE DIED OF A HEART ATTACK!!
-Heroes wince in anticipation of dying-
Mob Leader: -shouting- AND TO TOP IT ALL OFF -beat- that guy was a major jerk so we’re actually in your debt.
[quote] “Just_Asking_Questions, post:39, topic:961002, full:true”]
That’s not really script dealbreaker, more of an acting thing, but by have I seen it.
[/quote]
I disagree. I think it’s in the script because it’s FUNNYᵀᴹ
HE: Are you afraid?
SHE: (Snuggling up) No … not any more. 
Yet can’t hit the good guy from 10 feet away.
Like here:
“This time it’s personal.”
Like the last 100 times the bad guys tried to kill you, kill your partner, abduct your wife, etc. it wasn’t personal?
Okay, the Evil Overlord list is not actually a dealbreaker, but it does have a lot of cliches seen over and over. My favorites are #48 and #100
The Pioneer Women’s Rifle, which when fired in the air with eyes closed will hit a circling brave at 100 yards.
Racking the slide on a pump shotgun. Cocking a double-action revolver.
Fiddling with the ejector port on an M3 submachine gun. Pulling the slide on a .45 automatic all the way back to see if there’s a bullet in the chamber (and ejecting a perfectly good bullet in the process).
( Chuckling ) I actually saw somebody do that IRL, not to check for the presence of a round, but thinking they were cocking it somehow. At least they didn’t hold it sideways. 
I remember one early episode of Sleepy Hollow where Ichabod fires one shot with the pistol Abby gave him and then drops it, because his experience with (18th-century) guns is that you can’t load and fire again with the enemy that close and you’re better off getting your hands free and finding a melee weapon.
The TV show Police Squad! used to make fun of this trope all of the time.
It’s an entirely different kind of dialogue, altogether.
I’d bet money that that happened when Rush Limbaugh appeared on the Drew Carey Show. Everyone who met him said “Oh, Rush Limbaugh! I love your show!” Made even more of a cinch because he was known for never appearing in the media where he could be challenged. It wouldn’t surprise me if he had veto power over a take he didn’t like written into the contract.
I think this covers pretty much everything.
[What a Guy! | Red Dwarf | BBC Studios - YouTube]
“I oughta kill you right now!” [Points gun at hero, then politely waits for hero to talk him out of it]
“Ah, he plays with death as if it were a toy!”
Another really specific bad line that pops up all the time.
Character A is being given an impossible or bizarre task to do by Character B in front of Character B’s cronies. Character A responds back in shock repeating the orders and Character B assumes this means he’s actually all in and it leans on the 4th wall enough to make it annoying.
B: I need you to rob Fort Knox using only a Model T car and get away with 10 million dollars.
A: Wait hold on, you want me to rob the most heavily guarded bank in America with a 100 year old car and somehow get away with it?
B: Now that’s a beautiful summary I’m glad you understand it!
A very common action cliche I’ve mentioned in probably more than one similar thread:
The good guy beats the bad guy in the final battle.
Bad guy: Go ahead, finish the job. Kill me!
Good guy: No, I’m not like you.
Good guy turns and starts to walk away. Bad guy removes hidden weapon or grabs nearby dropped weapon, forcing good guy to whip around and kill him in self-defense. Thus good guy gets to keep his virtuousness, and audience is spared an anticlimactic ending.
Character A: [completely ludicrous and bizarre statement]
Character B: [opens mouth as if about to correct Character A, then purses lips as if thinking “What’s the use?”]