So, If I say “Elvis impersonator”, you visualize someone dressing up as a small bearded Scottish guy with glasses?
No, but I’m a huge Elvis Costello fan and the mention of just “Elvis” wouldn’t automatically make me thing “Presley.” Just’ sayin’.
ShadiRoxan, was your post (“How about Sigfreid and Roy?”) in response to the previous one by Lute Skywatcher (“Don’t forget Tiger.”)?
Because I’m pretty sure neither Siegfried nor Roy will ever forget that tiger…
Yanni
Charo
Penn and Teller
Cathy (comic strip-she has a last name)
Moby
Galileo. For some reason, his last name (Galilei) is almost never used. There must be something about astronomers, because I’ve noticed that Tycho Brahe is almost always referred to as Tycho.
I’m not sure these guys count as celebrities…
Gilgamesh
Hammurabi
Moses
Zoroaster
Plato
Jesus
Muhammad
Actually it wasn’t. It just worked out to nice timing I guess.
To continue Jomo Mojo’s trend… 
Confucius
Socrates
Sophocles
Aristotle
More seriously:
I’d lay odds on Alanis, but that could just be because it’s not that common a name. Same thing for Celine, I bet.
Garth
Macauley
Ewan
Reba
Wynonna
I want to say “Jack”, but I maybe wrong
“Bruce” would be for me, but there’s at least two other people that could come to mind for other folks. Same for “Dave”.
Mel
Cecil?
Melanie
FTR, Roseanne has apparently gone back to using Barr as her last name. At least her most recent film credit, Home on the Range (voice) lists her as such, and I hear her announced as an upcoming guest on talk shows, and on entermation shows, as Roseanne Barr.
Affleck. I guess it isn’t as obvious as I thought it was, although I’ve seen a number of Surviving Christmas reviews with headlines simply stating “Ben’s Career Is Over” or “Bad Ben”, which seemed like the final nail in the coffin on the name Ben.
and when I wrote the OP, I was refering not to people who go by one name themselves, but by everyone else whose brains can collectively ring a bell and point to one particular person just by hearing their first name
Even when she was Roseanne Arnold, I remember pretty much everyone kept using the Barr name.
Well, I certainly don’t want Ben Affliction to be what i think of when I say Ben. I’d rather have Ben Stiller, thankyouverymuch.
Bleh.
AHunter3, hey, Melanie was a good call. Glad to see another old timer who can remember the ‘70s. I can’t believe my memory not only stored but can actually recall Melanie’s last name: Safka. Which makes me wonder: how many serious trivia hounds can name these monomonikered celebrities’ last names without needing to look them up?
Chèr Sarkisian
Madonna Ciccone
Yanni… ? I’m stumped, I never learned Yanni’s last name. Which reminds me of “El Greco” (Last name: Theotokopoulos).
Enya’s last name is Ní Bhraoinain (or something like that… I can never remember how many extra vowels to pack in when trying to spell Irish Gaelic). But her last name applies only if you spell her first name the original way: Eithne.
Darnit. I thought about her, too. Still have her ‘Candles in the Rain’ LP. I don’t think any other artist came up with roller skates as a metaphor for dancing the horizontal bop. 
Regarding the OP - Who is Christina? The only one I could think of was Applegate, but she’s sort of off the radar these days.
StG
That’s Christina Aguilera.
Kat - That’s right - I’d forgotten about her. These days she’s almost as off the radar as Christine Applegate.
StG
World-wide, I’d say the “Ben” most people would think of would be Ben Cartwright.
After all, Bonanza episodes are still shown nearly every day, in a whole lot of countries all around the world.
Priscilla Black?