Those are very good options, but maybe you should add one more: Wolverine. Now, I'm not saying it's my favorite, but in its relatively short existence, Wolvie has gathered a very solid fanbase.
This been said, my vote goes to Batman. Aside from being my favorite due to his none alien/accident origin, which is the most easily recurred, Batman is pretty much known all over the world, and his comic books, movies, series, and merchandise in general are still seen around.
It's true that Superman was the first one, and thus is somewhat archetypical of the superhero (the very name actually comes from him!), but nowadays is somehow cast as sort of an "old school" character, being noted that writers have a lot of trouble writing good stories about him.
Spider-man IS the most popular superhero from Marvel, but somehow has also fallen into that "what do we do next?" thing, but also you can see his image all over the world, and people still remember the 1960's tv theme. Try singing it somewhere, people may not know the lyrics, but they will sure remember the character and the series.
Batman, of course, has entered the "old school" genre too, but I think somehow due to the latest hype over "how well written are the movies about him" (actually those two movies are like "in between events" for any die hard fan, and Heath Ledger's Joker, though wonderfully played, still pales in comparison with "the real" Joker), Batman is still present and now closer to what the character really transmits in the comic books. The latest Superman installment, tho taking and paying homage to Richard Donner and Christopher Reeve's classic, was rather mild, even with Kevin Spacey as Lex Luthor. Let's admit it, the story was frankly dissapointing. And Spider-Man's third is a proof on why superhero movies eventually flunk: my respects to Sam Raymi for the first one, but retelling the same story over and over, altering continuity beyond any recognition only ends up in those superhero movies from the eighties. Also, writers, if you kill the villain in the end as a rule, you end up the conflict, and dear sirs, the conflict in comic books is never ending... get it now?
Okay, enough movie talk. I've explained my reasons, and my vote goes to Batman.