The Milwaukee suburb of New Berlin.
Pronounced New BER-lin, not like the German city of ber-LIN.
New Prague, MN. Actually pronounced ‘praig’ and not ‘prahg’.
Kissimmee, FL. Pronounced ki-SIM-ee. Tourists usually go with KISS-a-me.
Shakopee, MN. Pronounced SHAK-o-pee. Usually hear non-locals call it sha-KO-pee.
There are a ton here in Massachusetts, but my favorite is Quincy (“kwin-zee”).
My GPS tells me to take the exit to Tarentum. The town is Ta-REN-tum but my GPS says, TAREN-tum.
A lot of people from the east coast say Oregon wrong.
And don’t get me started on Puyallup and Sequim.
Ansonia, Russia, Lima and Versailles Ohio. Within 30 miles of each other and atrociously (and proudly) mispronounced by the locals. They pronounce them Aunt-Sonya, Rue-she, Lie-Ma and Ver-Sales.
Worchester Massachusetts as well, they pronounce it Wooster.
I believe that Detroit is mispronounced as well from its French origins.
I pity anyone who actually speaks French when they visit St. Louis
grav-OY for Gravois
Day PAIR for Des Peres
Kuh-RON-doe-let for Carondolet
It’s not a town, but most people mispronounce Kiribati unless they have some familiarity with the Pacific region. (It’s not “kiribatee,” it’s “kiribas.”)
Mt. Desert (the town and island in Maine), should be pronounced like Mt. Dessert, not like the Sahara.
Buena Vista, Colorado is pronounced BEW-na Vista. The better your Spanish, the worse you’ll do on the name.
“Regular old” BERlin, up by Oshkosh, is the same.
And Peabody, which I understand is pronounciated “Peebud-ee”
These were the first to come to mind.
AIUI: “pwee-lip” and “sqwim”.
Also, Yreka, CA.
As well as Berlin, New Hampshire, and Berlin, Pennsylvania.
Indiana has a couple of towns whose names are the same as better-known cities elsewhere, and pronounced differently:
Carmel. Pronounced CAR-mul, unlike the one in California, which is pronounced car-MEL.
Galveston. Pronounced Gal-VEST-un, unlike the one in Texas, which is pronounced GAL-vuh-stun.
We also have Russiaville, which is pronounced ROOSH-a-ville, and Vevay, which is pronounced VEE-vee.
Your issue is with the OP, not my post.
Never mind, you were editing while I was composing mine.
Dr. Kate Pulaski : Dah-ta, look at this.
Lt. Commander Data: [looking slightly confused] ‘Day-ta’.
Dr. Pulaski : What?
Data : My name. It is pronounced ‘Day-ta’.
Dr.Pulaski : Oh?
Data : You called me “Dah-ta”.
Dr. Pulaski : [laughing] What’s the difference?
Data : One is my name. The other is not.
BERlin is the name, BerLIN is not.
Thank the kaiser for that. At least we can still eat sauerkraut on out brats, not victory cabbage on our roast pork sausage.
And Berlin, CT and many others.
I’ve yet to hear of the US city that doesn’t pronounce it BER-lin. What I was told growing up in MA, where there is a Berlin, is that the towns changed the pronunciation during WW2 to differentiate them from the German city. I’ve never been able to find a source to verify that.
From Wikipedia, on Berlin, WI.
Area residents put the accent on the first syllable of Berlin rather than on the second. It has been said that this was in reaction to the anti-German sentiment that swept across the United States during World War I, and that the accent was previously on the second syllable.
My dad would pronounce it “BryLIN” just to be funny. You had to be there. 
Isn’t that more of general Midwestern dialect? I’m from Ohio and I pronounce the name of the Czech city as the former (/pɹeɪg/). The latter (/pɹɑ:g/) sounds like what I imagine a New Yorker would say.
No one is getting it wrong. Pronunciations vary across dialects. While an individual has a natural interest in the pronunciation of their own name, locations (as inanimate objects) do not. Describing the differences in place names is collecting information on dialects.
It’s more like PEA-buh-dee. Another favorite in the Boston area is WOO-burn (for Woburn).
I pity new on-air hires at Boston radio and TV stations who face a minefield of incorrect local place name pronunciations. I suspect that they’re issued a handbook before they start work, or are obliged to listen to WBZ for a few days.
The Bitchin’ Bettys on our phones’ GPS systems are incapable of pronouncing Man O’War Boulevard in Lexington, Kentucky correctly. We get all sorts of variations.
Also Milan, NH, pronounced MY-lin.
And Calais, ME, pronounced CAL-is.