Usually as the summer approaches, it's easy to tell which blockbuster movies will be great and which ones will be lousy. But in the case of this year's four big superhero franchise movies, the Hollywood hype machine has done a remarkable job. As of today, anyway, the buzz on all four movies – Iron Man, The Incredible Hulk, The Dark Knight, and Hellboy 2 – ranges from fairly positive to overwhelmingly positive. But long, bitter experience with summer moviegoing assures us that there's no way all four of these films will be as awesome as everyone currently thinks they will be. So which one will overcome its great trailer, smart casting, and expensive action to be a total dog? Vulture makes the case for each, after the jump.

Why Iron Man might suck:
We've been told over and over again how perfectly cast Robert Downey Jr. is, but what if his smug snappiness makes Tony Stark completely hateable? More than that, the character himself doesn't inspire a lot of sympathy; kidnapping-inspired turnabout aside, is America really ready to identify with a billionaire arms dealer, no matter how many little old ladies he saves? As for the film's presumed box-office triumph, no amount of marketing muscle can change the fact that even though Iron Man's a crucial character to comic-book aficionados, to the general public he has nowhere near the Q-meter rating of Spidey or Supes.
Odds it won't be super? 5:1.

Why The Incredible Hulk might suck:
Lou Ferrigno's appearance at Comic-Con aside, there's been plenty of behind-the-scenes drama this spring involving the big green guy. Star Edward Norton reportedly has been unhappy with the direction Marvel's taken the movie, and the initial trailer made the movie seem exciting but shallow and somewhat humorless. And if a legitimately great director like Ang Lee can't make the Hulk story into a good movie, what chance does Louis Leterrier (previous credits: The Transporter, The Transporter 2) have?
Odds it won't be super? Even money.

Why The Dark Knight might suck:
Christopher Nolan's last take on the Batman mythos was intelligent and crisp, but did Batman Begins' gloomy vision of Gotham really deliver the pop thrills you might hope for out of a superhero movie? The Dark Knight seems even, well, darker, and Heath Ledger's psychotic-seeming performance as the Joker — and the pall put over the entire project by Ledger's death — doesn't do much to make the movie seem like, y'know, fun. What if the entire thing is a self-serious slog?
Odds it won't be super? 2:1.

Why Hellboy 2 might suck:
We're a huge fan of Guillermo del Toro, but Hellboy creator Mike Mignola's comments last week that the new movie represents Del Toro's vision more than his own didn't inspire a huge amount of confidence. Neither did the trailer, which is so overstuffed with Pan's Labyrinthine creepy-crawlies that Hellboy's trademark wit gets lost in the shuffle. Most of all, this is the superhero movie we're most looking forward to this summer — which makes us all the more nervous that, in the tradition of past so-called sure things Hulk and Spider-Man 3, it'll be lousy.
Odds it won't be super? 3:1.