Yeah, Edgar Allan Poe is the only one that came to mind with that spelling (don’t know what an Allan doll is), and that “Allan” is actually the last name of his adoptive family (his father abandonded him and his mother died when he was almost 3.)
Alan, because it’s the spouse’s middle name and I’m a huge Alan Parsons Project fan.
Mine too.
Charles, though it looks funny as a first name. IMO, of course. 
Just curious: how many Charles Greg (Gregg most likely) do you know of?
Alan as a first name, Allen as a last name. I picked “Alan,” assuming that the OP was interested in first names.
BTW, I do have a friend with the last name “Allyn.”
I voted other. My reasoning was identical up to the last part.
Just to clarify: when you say “people you know of with the name” are you including those who have it as a last name?
As a first name: Allan.
As a last name: Allen.
People who spell it “Alyn” are not to be trusted and probably from Canada.
Sure. I’m very sorry my wording was iffy in the OP. I should have said “the name in any position in a person’s appellation” if I had been thinking of how it might be misconstrued.
In my own experience, I find it rare that Alan is a surname, where Allen is often such.
All three are seen as given names, with Alan probably most frequent.
I only put Allyn in the poll because I have at least seen that spelling somewhere along the way.
Allyns exist? Really?
Reminds me of the old Dick Van Dyke show where Laura was pregnant–no wait, you couldn’t say that, it was “expecting”–and Rob’s boss Alan Brady (played by Carl Reiner) gave Dick a list of ways to spell Alan so he could name the baby after him.
Allan as a first name, Allen as a last name.
A year or two ago, I had a student named “Alon.” Pronounced the same as the other choices. Likable kid.