I choose to pronounce testicles like Heracles.

I say appree-see-ate for appreciate, and artif-isss-ee-al for artificial.

I pronounce dragon as dragòn, if you know what I mean.

Two immediately come to mind.

First is "Comfortable". I pronounce each part of the word: "COME-for-tuh-bull". Many people give me weird looks and insist on "Comf-turr-bull".

The other is more niche and has to do with League of Legends.

There is a champion whose theme is moonlight. His backstory is that he belongs to a moon cult who opposes a group that is am Order of the Sun type group. This character is an edgelord whose whole thing is darkness and midnight etc etc.

His name is a combination of the Greek "Ap" meaning "furthest from" and "Helios" meaning the sun. His name is Greek for "the one furthest from the sun" in this moon cult.

In Greek, "ph" does not make the "fuh" sound. His name should rightly be pronounced "App-Hee-lee-ose"

But all the casters and developers call him "Uhh-fell-ee-ose" and it drives me absolutely insane.

I pronounce "beautiful" as "be-ee-ah-ou-tee-ful" like it's 6 syllables.

A long time ago I heard a radio (I'm old) caller saying they pronounced it that way to help them spell it, and i got infected. I never had an issue spelling it, it's just so interesting that I can't help myself.

I'm Dutch. I pronounce the -en at de ends of words, including the n. If you don't know, that's like 10% of all Dutch words

My SO's family all like to pronounce "mauve" in a weird way, so I say it every chance I get to perturb them.

Bala-tro, not Ba-lottro.

The way Midwestern Americans say "roof" bothers me.

Agate. Apparently I pronounce it the British way rather than the American way because I had read the word many times while never having heard it spoken aloud.