Wednesday Friday Addams. Weren’t she cute?
They aren’t common, but IMDB searches reveal at least one American in Hollywood for each day of the week. Whether those are given or assumed names, I don’t know.
An astonishing number of “Tuesdays”, incidentally.
Ian, Nigel - very British (from a US perspective, at least).
Gordon - generic suburban Canadian guy; someone who drinks Molson, drives a Pontiac, eats ketchup-flavored potato chips, says “eh” a lot, and plays curling.
Bruce, Todd - gay man.
Stan - in Buffalo, a typical Cheektowaga resident; very Polish, very devoit Catholic, extremely blue-collar, speaks in a strong clipped Polish Buffalonian accent, accomplished bowler, is a volunteer fireman, Bills fanatic, etc.
And if he’s Gordon McKenzie, he plays skip.
Dieter is German Eurotrash
Silvio is Italian Eurotrash
Raul is Spanish Eurotrash
Rene is French Eurotrash
Irv, Sid or Morty: Reform or Conservative Jews.
Stella, Alfreda: the female equivalent of Stan in Buffalo.
Randy: just about every general contractor or good 'ol boy developer I ever met when I was living in Florida.
Shaniqua: the quintessential urban black woman.
Sunshine: female offspring of 1960s-era hippies.
Heidi: Blond German woman, often with ponytails.
‘Ahmed’ and ‘Abdul’ are common slang (and ignorant) stand-ins for Arabic male names. (Even though ‘Abdul’, IIRC, isn’t a complete name. Means “servant of…”)
I’ve heard that ‘Muhammad’ is the most common given name in the world. The most common surname is ‘Chang’, from China. But I don’t know of many 'Muhammad Chang’s running around.
Aren’t names traditionally done last name first in Asia though? So you might have more luck looking for Chang Muhammads.
Wayne, Darren and Jason are the preferred names of the criminal classes here in Australia.
I had that book, and I’m pretty sure you mean ‘Rufus.’
Wayne seems to be a common middle name for murderers in the States.
“Vera, Chuck, and Dave.”
Dunno if you mean Irish Irish or American Irish, but I’ve never met an Irish person, male or female, called Patty. Pat, Padraig, Patrick, Pakky or Paddy, but not Patty.
I have. She was a good friend in college. Her last name was Berger which she never figure out if her parents realized it before they named her that.
“Berger” isn’t an Irish name. German or Scandawegian, I’d say.
And probably of Scottish background! 
Thant’s funny, to me Tiffany is associated more with the upper-class WASP types - sort of a female Tad.
Heidi is classically Swiss. Hans and Franz are in fact Austrian and want to pump CLAP you up.
And if Wolfgang and Helga move next door, leave the country before sunrise.
Your archetypical Canadian is called Gord or perhaps Janet.
Joanne is Catholic and from Buffalo. Her ancestry may be Irish, Polish, Italian, German, Lithuanian or any admixture thereof, but she is from Buffalo and she is Catholic. If she’s Greek Orthodox, however, she’s Joanna.
Just about any female born after 1950 can be Lisa.
A genteelly prejudiced relative of mine once claimed Lisa was a “Jewish” sounding name. I reminded her she’d named her own daughter that.
Nah, Tiffany is a ditzy teenager. Tad’s companion is Muffy.
You sure you don’t mean Tammi? (dotted with a little heart, natch)