“Nithulanian” instead of “Lithuanian,” as in The Music Man, when someone refers to poor Tommy Djilas, whose father is “one of those Nithulanians lives out south of town.”
Worcestershire sauce is whazzizhere suace.
We frequently whet our appetites with horseovaries.
I am posting to y’all over the intartoobz.
The big box in the kitchen that keeps food cold is the refrigidaireator.
Florida is Floriduh.
Georgia is Jawja.
The Carolinas are the Keeroliners.
I’m a walking mispronunciation guide.
I say “roof” like “ruff” because it sounds a little more Canadian.
Also:
Kuh-nife, Skizzors, po-leece
and of course “Amber Lamps” for ambulance.
How could I forget goatmeal? I eat it all the time.
I say Fuh - BREWery, like it was a beer brewing month.
I call it a bambilance, considering all the deer I’ve hit while driving one.
The nut is a PEE-can, not a puh-CAHN.
Another one for the little dog being a Cha-hoo-a-hoo-a; sometimes I use SHE-wah-wah.
Hors d’ouerves are horse doovers.
The discount store is Tarzhey.
In our house, we eat skabetty ‘n’ meatballs.
My son, as a pre-schooler, insisted the first meal of the day is brefkist. The name has stuck. When I was little, the things that cleaned the windshiled of rain were windmill shwipers, and that name stuck around until I was out of college.
I once met a crusty Marine who made a comment about the Cadillac SUV, the “Es-ka-lady.”
It still cracks me up, but I don’t think I’ve ever had an opportunity to use it.
Mosquito and pterodactyl are ‘mosquinto’ and ‘petridactyl’ respectively. I also use Les Nessman’s ‘chihooahooah’ pronunciation from time to time.
I sometimes will spell out Roman numerals. “Yeah, I’m watching Star Wars Episode Vee” instead of five.
Related: I might say Mac OS X as “Mack Oss Ecks”. As a non-fan of Apple, I like to annoy the iFanatics.
K-niggits. As in “You so-called Arthur King and your silly English k-niggits!”
New Orleans is N’Awlins, which is how they say it.
Same with Joisey for New Jersey.
Herr Hilter, as in “Hilter ist gut für Minehead!”
I don’t actually do it but I have an urge to pronounce “Celebrate” like a cross between Latin and Elvish, i.e. Kell-uh-BRAH-tay.
NOBODY from New Jersey says “Joisey.” It’s a NY thing.
Heimlich Maneuver = “hymen remover”.
I pronounce it the way it SHOULD be pronounced (wer-ches-ter-shure). Sometimes I even add another superfluous syllable to the end (wer-ches-ter-shure-shure).
Yeah, like “Hurt is hoyt!” and “New Greenpernt.” 
Those noble Greeks, So-Crates and Hippo-Crates (I don’t know how Bill and Ted pronounced them)
Same here – War Chester Shire Sheer sauce. I think I heard that one from a TV show, but my memory fails me.
When I first learned of that word I looked up the proper pronunciation and waited until the day I could use it. But my mother beat me to it and pronounced it “para-didj-um” and then the opportunity arose for me to use it and I, of course, pronounced it the way she did. When I was corrected I said, “yeah, I knew that. My mother screwed me up.” Which turns out to be the answer for a lot of things.
This is what I intended to post.
I like going up to cashiers and saying “Hello. I would like to purchass these itehms.” Not once have I ever gotten a weird look for it.