The trouble with Harry in Hitchcock's dark comedy is that he's dead. But that may be the only place he's dead, because he seems to be alive and well in literature.
Even leaving aside Harry Potter, there's an amazing number of characters in novels named Harry, considering how few you meet in real life. I'm not sure I've met a live Harry since the 1950s, when my Dad worked for Harry McKee. (One Internet source tells me it currently ranks 656th among masculine first names in the U.S.)
Several books I've read recently feature Harry as the hero. Jim Bruno's fine thriller, Tribe, features Harry Brennan. Bruno clearly references Clint Eastwood's Dirty Harry character, to the point you can almost hear the actor growling the dialogue in the book. (Casting him in real life would involve some time travel since Bruno's character is a good deal younger than Eastwood is now.)
Another recent e-book, The Essene Conspiracy by Erich Wachtel, had Harry McClure as the hero and Wachtel clearly intends to build a series on this character. Harry seems to work particularly well with Irish surnames. Dirty Harry's last name is Callahan.
But not necessarily. One of my favorite authors, Robert Goddard, has written at least three books with Harry Barnett as the main character. And Michael Connelly's long-running series features Harry Bosch.
I'm giving this a lot of thought right now because I need a new name for the hero of my work in progress. It is a contemporary political thriller starring an American journalist based in Berlin. I started it some time ago and am just now getting back to it.
I think part of the appeal of Harry is that it has an old-fashioned masculine allure, like Frank or Max. Authors don't usually like the John, Jim, Bob, Dan, Bill and Doug you encounter so often in real life, especially if you are going to refer to him routinely by his first name. It may be the very rarity of Harry in real life that makes it appealing in fiction. Other less common first names -- like Mark, Carl, Phil, and so forth -- don't necessarily have that biting masculine quality you want in a thriller hero.
So some authors really venture outside the box. John Locke's hero is Donovan Creed, which I think works really well. Donovan is for me a singer from the 1960s who just uses a single name. Locke hardens the slightly effeminate ring of Donovan with the sharp-edged surname of Creed -- a guy you can really believe in.
Right now the best I can come up with is Sam Riley. Sam of course is in the Harry, Frank, Max category of tough-guy names -- e.g. Sam Spade. So I'll work with that name for a while and see how it goes.