GMs: What have you seriously thought about adding to your campaign...

Women in leadership positions

Are you kidding? That's a great plot point.
"Woman in charge fucks up everything - 'We should have made her brother king instead,' says ignorant peasant."

Thrallherd?

I thought about playing Rifts, but then I remembered the whole thing is fucking retarded.

More or less.

In gurps translation.

An arc involving a fat nobleman leading a cannibal cult behind the scenes and his two, sort of lich bodyguards.
I was going to base the nobleman on Paul Bearer, complete with horrible falsetto, and the bodyguards on Undertaker and Kane.
None of the ideas I had felt right, and if anyone caught on they'd realize I was a hack.

More complicated death mechanics. Scars and stat changes and weaknesses and shit as a result of getting dropped. I opted instead for granting players and monsters bonuses on crits, which has gone over well. It's also way less complicated.

Not too stupid or cringeworthy, just way too powerful...

Dude, I think playing an Overlord style character with Ally would fucking insane. Perhaps fun, but perhaps also involving too much micromanagement. The idea, at least, is deeply amusing.

It’s actually an aura that conditions people with fanaticism towards me.

I can turn it off but, again I chose not to play this guy.

Maybe because nobody in my party had enough willpower to not be a fanatic.

Do it you fucker

My waifu. I don't even mind if the players rape and kill her. Just having her in the game for a moment would make me happy.

considered running a game in my cringeworthy headcanon universe
was going to be a simple horror/military game where they are part of a mission to recapture a city
only to find that the enemy has used it to make biopunk horrors
and the further they go in the more traces they see of these giant things that glisten with amniotic fluid and have chain guns strapped to their arms
and at one point they try to go through a door but it jams part way when half the squad is through, and all they hear on the other side is slashing and screaming, then blood spatters on the tinted windows
had all sorts of ideas for what they would find there
but it felt wrong to do
also I realized that if they google-searched the names of the guns that would be available to them, they would find all my autistic shit and i would never be able to talk to those people again

Sewerslam. A bunch of ogres doing pro wrestling style "mud" wrestling in the sewers of the capital. I was worried my players would assume it was supposed to be magical realm instead of horrifically disgusting.

Stealing that idea

I've considered running a game where WW2 never ended. When the allies invaded Germany, they discovered the Nazis had infected their entire military and concentration camp populations with a zombie like virus. The standard ground troops were nearly brainless, but could be ordered by the officers (through the use of special zombie pheremones or something) to perform task to a rather satisfactory point. The officers, while also zombified, retained their intelligence. The resilience of the zombie troops allowed them to push the allies out of Europe. Bombing campaigns went from "drop 1000 bombs and try to kill as many people as possible" to "load 100 zombies into a rocket, and fire it at X country". The story was going to take place in the 1980's (after 40+ years of war), and revolve around a spec ops group assisting the resistance in Europe and killing the officers that controlled the zombies. Each session was going to be based on a song (Killer Queen, Guerilla Radio, War?, etc...)