Cicero, IL: Al Capone
Aspen: snooty ski resort
Zermatt: ditto
Munich: Olympic massacre, Beer Hall Putsch
Kocs: birthplace of the coach
Heidelberg - Dueling scar.
Port Arthur
West Point
Appomattox (w/ or w/o “Court House”)
Auschwitz.
Buchenwald.
Dachau.
Treblinka.
And a lot more. Sadly, all for the same thing.
I’m not sure if these are well-known in the US, but they’re instantly recognisable in the UK.
Lockerbie: the Lockerbie air disaster
Dunblain: the massacre at a primary school
Most of the cities that came to mind immediately were already taken. So here are a few I thought of:
Homestead, FL: Hurricane Andrew.
Utrecht will probably always be remembered for its eponymous treaty. Ya know…the one that ended the war of Spanish Succession.
Paducah, KY: Another school shooting.
Breezewood, PA: The “city of motels.”
Runnymede: I hear that Magna Carta thing was pretty important.
Dunkirk.
Chicago–for the Great Fire, for the Saint Valentine’s Day Massacre.
Mufreesboro - people who don’t read the OP carefully enough 
Antietam
Anzio
Vicksburg
I guess you could go on forever with towns at or near battlefields.
Warsaw - Jewish Ghetto and The Uprising
San Francisco - gold rush, earthquakes, Golden Gate Bridge, Alcatraz, If you’re going to San Francisco, Be sure to wear something groovy in your head… (is that too many?)
Oranienburg and several others - need I say?
San Juan Capistrano - swallows
Pensacola - US Navy
Houston - oil, cowboy cops, NASA
Miami - cocaine, hurricanes
Tokyo - formerly billion dollar buildings, people, the Emperor, people, Mt. Fuji, people, fire-bombing, people, Hideki Tojo et al
Well, I’ll leave some for the rest of y’all.
Yeah, well, I went back and read the OP before I posted, but not the damn title. Cut me back to:
Antietam
Anzio
Vicksburg
Oranienburg
San Juan Capistrano
Pensacola
Roswell, NM–aliens
Killeen, TX–Luby’s Cafeteria massacre
Waco, TX–wacko pseudo-religious nuts
Texas City, TX–chemical plant explosion
Brownsville, TX–ritual killings of tourists by “satanic” border mexicans
Three Mile Island and Chernobyl (assuming those are proper towns)
Tunguska, Siberia
make that Mufreesboro AND Houston 
Carlsbad
Nanking
Dien Bien Phu
Rhodes
I’d wager Ft. Hood comes to mind before Luby’s more often than not for Killeen.
Ft. Lauderdale - Spring Break
Matamoros - Boys Town
Beirut - civil war (or whatever you want to call it)
Las Vegas - Bling! Bling!
Some more:
Cooperstown,NY
Menlo Park,NJ
Paris,Ky.-home of horse brothels
Promontory point,Utah
Cape Kennedy (nee Canaveral) Fla,
Weeki Wachi Springs,Fla. home of the underwater mermaid show.
Ossining,NY-Sing Sing
Palm Beach County-chads
Lynchburg Tenn.-sippin’whiskey
Atlantic City-salt water Taffy
Saratoga Springs,NY.-racetrack
Brooklyn,NY,-dem bums (at least to the oldtimers)
Andersonville
Cicero
Kent
Indianapolis
Monte Carlo
Berlin, Germany
Lexington and Concord, MA
Chattanooga Choo Choo
<nitpick> Parris Island, SC </nitpick>
Best Summer camp ever
Madras
Buffalo, NY - Blizzard of '77, where it really didn’t snow much, it just blew the accumulated snow off of ice-covered Lake Erie.
Plains, GA
Chappaqua, MA
South Bend, IN
Baghdad, Iraq
Tehran, Iran
Bhopal, India
Pompeii, Italy
Giza, Egypt