Some day it might even be as well known as the Lone Ranger Theme.
That’s the William Tell overture
I think Little Nemo knows that.
Right. Which long ago became “The one with the cannons!”
But that’s a bit beyond the scope of the OP.
Willy Loman
If we’re considering characters whose names have become common words, certainly most of us understand “gargantuan” as a synonym for gigantic, and many know Gargantua was the name of a giant in a series of novels by Rabelais, but fewer know that he appeared in an earlier novel by an anonymous author, and even fewer have read the source material.
I wouldn’t count Dracula, since the novel is well-known and continues to be read, especially by people with even a casual interest in vampires. Instead, I’d look to his predecessors whose names may be forgotten but who left their mark on their genre. Vampires of folklore might be found among peasants, but Lord Ruthven of “The Vampyre” was an aristocrat whose victims were also members of society, which remained the standard for many years. Varney the Vampire seems to have established the idea that vampires have hypnotic powers, unusual strength, and fangs, and leave puncture marks on their victims’ necks. Graf Orlok (who was based on Stoker’s Dracula but predated Lugosi’s) may have been the first vampire to be destroyed (as opposed to weakened or repelled) by sunlight.
I don’t think mythological figures whose names became common nouns should count. Being mythological, their origins can’t really be pinned to a specific work of fiction.
I was going to mention Faust, but a few seconds of research revealed that Faust was a real person, so I’ll mention Mephistopheles instead. The name appears in a text ascribed to Faust. But the concept of Mephistopheles as a demon with whom a mortal enters into a Faustian bargain appeared in an anonymously authored collection of stories (“the Faust chapbooks”) which is not nearly as well-known as Marlow and Goethe’s versions.
Every time something in politics appears to be happening over and over to no good end, you can bet the pundits will make sure the movie Groundhog Day gets mentioned. 
Scrooge.
Yeah, I misread his post. I mistakenly thought that he said that “ride of the Valkeries” WAS the Lone Ranger theme. On rereading I see that he didn’t say that.
You forgot Carmilla and all the lesbian vampire genre.
That must result in a lot of confusion for fans of the 1812 Overture.
I thought about it, but I think lesbian vampires may have been inevitable with or without her.
Dammit, I knew I was going to do that!
Simon Legree (from Uncle Tom’s Cabin). Also Uncle Tom. Both are now archetypes (that may not bear great resemblance to the originals), and although the name of the work is probably still pretty well known, how many people have actually read it?
Roddy
With any known make of gun I could have killed Gregory Fitzhurst at three hundred feet with my left hand.
It’s not quite a character as such , but I suspect that many more people will recognize what Lilliputians are than have read . . . . (thinks for a bit . . . not Robinson Crusoe . . . ) Gulliver’s Travels.
Odd that the name Gulliver probably won’t be recognized nearly as much.
But Gilligan, however…
Oh! Gulliver’s Travels also provided the name for the Internet behemoth Yahoo!
<The Web site started out as “Jerry and David’s Guide to the World Wide Web” but eventually received a new moniker with the help of a dictionary. The name Yahoo! is an acronym for “Yet Another Hierarchical Officious Oracle,” but Jerry and David insist they selected the name because of its definition: “rude, unsophisticated, uncouth.”>
http://yhoo.client.shareholder.com/press/history.cfm
<ETYMOLOGY: From Yahoo, member of a race of brutes in Gulliver’s Travels by Jonathan Swift.>
I honestly thought you did that on purpose.
I’m sure more people know who or what a Man Friday is than have ever read “Robinson Crusoe.”
And everybody knows who Jeeves is but few have read Wodehouse, though probably more than a few have seen a bit of Fry and Laurie.
We’ll go with that then. 