Twilight Without Robert Pattinson?! Five Other Movie Casting Close Calls

What if Tom Cruise boarded Titanic? Jake Gyllenhaal suited up as Batman?! Billy Crystal took Buzz Lightyear to infinity and beyond?!

What if Robert Pattinson was out of the Twilight franchise's wedding-album picture? What if auditions for Edward Cullen had gone differently, and it fell to Prince Caspian (aka, Narnia star Ben Barnes) or Jasper Hale (aka, Jackson Rathbone) to walk down the Breaking Dawn aisle with Kristen Stewart?

What if?

Here are five other movies that would've looked differently had the "what if" casting scenarios become reality:

1. Titanic...With Tom Cruise (and Without Leonardo DiCaprio)?! When director James Cameron set out to make a big movie about a big boat, his studio set out to hedge its bets: It wanted a big star for the role of all-American kid Jack Dawson. According to the book, Titanic and the Making of James Cameron, the Cruise talk was more than idle, as the agent for the A-lister actually reached out to Cameron.

2. The Godfather…With Robert Redford (and Without Al Pacino)?! Yes, Hollywood does have a thing for big stars in big movies, so it's hardly a surprise that when filmmaker Francis Ford Coppola was prepping his Sicilian mobster saga, his bosses were pushing for the 1970s' leading man (who, no, didn't seem even vaguely Sicilian) to take on Michael Corleone.

3. Batman Begins...With Jake Gyllenhaal (and Without Christian Bale)?! Screenwriter David Goyer has described the Christopher Nolan production as being "torn" between the pre-Brokeback Mountain actor and Bale. That the Batman cowl eventually went to the latter proved to be a good break for Gyllenhaal's sister, Maggie Gyllenhaal, who wound up as the Caped Crusader's romantic interest in The Dark Knight.

4. Toy Story…With Billy Crystal (and Without Tim Allen)?! Pixar and Disney didn't just want everyone's favorite Oscar host for Buzz Lightyear; they really, really wanted him, going so far as to create special test footage so Crystal could see (and hear) what it'd be like for his voice to come out of Buzz's mouth. In the end, Crystal passed—"the only regret I have in this business of something I passed on," he later said.

5. Raiders of the Lost Ark…With Tom Selleck (and Without Harrison Ford)?! One of the most famous/infamous almost-was casting scenarios of all time. Just imagine: If Selleck's TV contract would have allowed, Thomas Magnum, and not Ford, would've taken refuge in the refrigerator in Indiana Jones and the Kingdom of the Crystal Skull? (See? These things work out for the best.)