Also, while I was explaining the concept to mum, I came up with "experts" -> "the guys down at the pub"
Friend of mine textreplaces "..." with "kupo" due to running into people who overuse it a lot. The end result in that he talks to a lot of moogles. So many moogles.
I had fun during the last presidential election cycle: Barack Obama => Gordon Freeman Joe Biden => Saxton Hale Mitt Romney => Wheatley Paul Ryan => Gray Mann Ron Paul => a defective turret I know I had someone mapped to Cave Johnson but can't remember who.
I was halfway down a really long Harry Potter AU post, when I got ambushed. Lots of extra text included to properly preserve the effect.
Upsides of textreplacing "Trump" and "Donald Trump" to "That Jerk": immense decrease in blood pressure. Downsides: a moment of extreme confusion on encountering the word "trumpet."
This is kind of a niche useage, but certain places on the Interwebs become a lot more bearable if you replace "I have AIDS" with "SAO was a masterpiece".
Spoiler: warning for "lolconsent" Essentially, "while you're having consensual sex with a girl, whisper this to her so she immediately wants to stop".