This year's summer movie season is all about asking "What if?"
As in, what if you had super powers and came from another planet? ("Man of Steel") What if the world came to an end and you were stuck at James Franco's house? ("This Is the End") Or what if you were pub-hopping during the end of days? ("The World's End")
 Blockbusters for the summer

How about if mankind was forced to leave Earth and the planet became inhospitable ("After Earth"), or if only the wealthy could afford to leave ("Elysium")? What if it were zombies that were our greatest threat? ("World War Z")

That's a lot of speculation, not the least of which centers around which of these movies could become hits and which are worth your box office cash.
Here's our guide to the top 20 summer movies:

May 24: "The Hangover III," "Before Midnight"
As Memorial Day rolls around, you have two trilogies to choose from: "The Hangover III" and "Before Midnight," the three-quel to Richard Linklater's accidental trilogy that began with 1995's "Before Sunrise" and continued with 2004's "Before Sunset."
In the presumed end to the "Hangover" franchise, the Wolf Pack reunites because Alan (Zach Galifianakis) is in crisis, and then they have to team up with their one-time nemesis, Mr. Chow, to retrieve something that was stolen. "It does not revolve around a wedding, and it does not revolve around a forgotten night," director Todd Phillips said. "It's a different structure."
In "Before Midnight," we catch up with lovers Jesse and Celine (Ethan Hawke and Julie Delpy) to see if they've finally made their relationship work, and under what terms, during a visit to Greece. "These films are the opposite of victory-lap sequels," Linklater said. "We've had six to nine years to think about it and dig in, and we wouldn't do that if we didn't feel that there was something new for them to say and some new station in life."

May 31: "Now You See Me," "The East," "After Earth"
Following Memorial Day weekend is the magic-heist film "Now You See Me," which squares off against star/co-writer Brit Marling's "The East."
"Now You See Me" is a glossy tale about four magicians (played by Jesse Eisenberg, Woody Harrelson, Isla Fisher and Dave Franco) who execute a bank robbery as part of their act (part of the fun is learning how the tricks are done).
"The East," meanwhile, is an indie thriller about a corporate spy infiltrating a freegan anarchist collective that executes "jams" on unsuspecting companies. Whether it's done by magic or terrorism, both films are about free thinkers teaming up to hold corporate America financially and morally responsible for its wrongdoings; consider them companion pieces.
Despite taking place in the future, at its heart, "After Earth" is a father/son survival story in which Will Smith tries to build his son Jaden's movie career -- er, tries to direct his son toward a rescue beacon. Smith's original idea for the film had the father and son crash their car in the mountains, but screenwriter Gary Whitta jazzed up the piece with a primordial planet filled with defense mechanisms meant to kill humans. "Earth has evicted us because we were messing (it up)," Whitta said. "If you took 'Jurassic Park' and dumped 'King Kong' in the middle of it, that's what you have in this environment."

June 7: "The Purge"
In "The Purge," a future version of America has decriminalized murder for a 12-hour period once a year. Those who can afford to do so either participate and kill off the have-nots or go on lockdown to protect their families. Ethan Hawke's character, who became rich selling security systems, finds his family besieged after his son lets in a man on the run. It's basically a home-invasion story with some sociopolitical underpinnings, but it'll provide some summer chills as the purge begins.

June 14: "This Is the End," "Man of Steel"
"This Is the End," which opens ahead of the weekend on June 12, will also provide a high body count but for comedic effect. Various celebrities are at a party at James Franco's house when the apocalypse occurs. "We thought it would be funny to see famous people die in graphic ways," star, co-writer and director Seth Rogen said. "We killed most of our favorite stars. ... Michael Cera plays a lunatic cokehead version of himself. He makes the best corpse."

Does Henry Cavill make the best Superman, though? "Man of Steel" is another reboot, this time with director Zack Snyder at the helm. Unlike the last Superman film, Bryan Singer's "Superman Returns" (2006), this is an origin story with a young Clark Kent realizing the scope of his powers and what he was out on Earth to do.

June 21: "World War Z"
Brad Pitt is also out to save the world, but only because it's infested by zombies. The producer and star of "World War Z" (based on Max Brooks' book) plays a former U.N. staffer caught up in a zombie pandemic. Pitt has said the film offered up a couple of challenges, and not just how to fight the undead: "How do we keep the global, dynamic scope of the book, and how do we originate a genre that's been done quite often and really, really well?" One of the solutions is to show the pandemic as it unfolds instead of merely documenting the aftermath.

June 28: "White House Down," "Byzantium"
Channing Tatum also plays the hero, but on a smaller scale. In "White House Down," he plays a man who has just interviewed for his dream job with the Secret Service and is on-site when terrorists storm the White House. He may not have gotten the job officially, but he in effect does it anyway by protecting the president (Jamie Foxx). Expect lots of explosions.
For a female-action alternative to most of June's fare, Neil Jordan ("Interview with the Vampire") has another story of the undead on the way called "Byzantium." Gemma Arterton and Saoirse Ronan play a mother-daughter vampire duo who've broken a cardinal bloodsucking rule of no females allowed. "It's a feminist movie," Arterton said. "Traditionally men, not always, are sexualized as vampires, not women. Women are the ones who are usually victimized."

July 5: "The Way, Way Back"
Sam Rockwell stars in the latest film from writing team Jim Rash and Nat Faxon ("The Descendants") as the owner of the Water Wizz water park who takes an awkward teenage boy under his wing. They head out on vacation with his mom (Toni Collette) and her boyfriend (Steve Carell). "It's inspired by real-life happenings," Rash said, "but it's heavier on the funny side than 'The Descendants,' even if both are dysfunctional family comedies." It won audiences over at Sundance.

July 12: "Pacific Rim"
Guillermo del Toro knows his monsters, and in "Pacific Rim," he brings to life his biggest ones yet: kaiju (Japanese for giant monsters). The film also features giant robots controlled by soldiers battling the race of alien beasts who rise from the ocean. There's a stellar cast as well (Charlie Hunnam, Ron Perlman, Idris Elba, Charlie Day and Rinko Kikuchi), but really, the selling point here is monsters vs. robots, right?

July 19: "The Girl Most Likely"
Kristen Wiig has her first post-"Bridesmaids" starring role in "The Girl Most Likely." Her character pretends to commit suicide to get a guy's attention, but the move backfires and lands her back at home with her mother (Annette Bening). "It's a comedy with an underpinning of real emotion, because this character is a hot mess and falling apart at the seams," co-director Shari Springer Berman said. "But it's Kristen, so you love her. Kristen can do anything."

July 26: "The Wolverine"
Hugh Jackman is back for another round as Logan in "The Wolverine," in what should be a stand-alone film within the" X-Men" series (hopefully erasing any bad memories leftover from "X-Men Origins: Wolverine.") This time, the story is from Chris Claremont and Frank Miller's 1982 comic series, so Logan is in Japan, where he meets up with a man he'd saved from a POW camp during World War II. Logan's lived a long time, but his friend offers him a way out: to make him mortal. In his way are Viper and Silver Samurai, the Yakuza and members of the Japanese criminal underworld.

August 2: "The Spectacular Now," "2 Guns"
An indie teen coming-of-age story ("Spectacular Now") starring Shailene Woodley and Miles Teller is no box office match against "2 Guns," but it'll remind audiences of John Hughes films that they love -- and make Teller a break-out star.
In the meantime, Mark Wahlberg teams up with Denzel Washington (and re-teams with his "Contraband" director Baltasar Kormákur) for "2 Guns," in which a DEA agent and a naval intelligence officer are forced to work undercover together as members of a narcotics syndicate, but neither one knows the other is also a federal agent. When they discover the truth about each other, they have to go on the run -- together.

August 9: "Elysium"
A little more high-concept is the much-anticipated sci-fi film "Elysium," starring Matt Damon and Jodie Foster and directed by "District 9"'s Neill Blomkamp, about the wealthy living on a space station while the impoverished live on a polluted planet. "It's not a sequel; it's not a franchise," Foster said at San Diego Comic-Con. "This is completely original, and it has a real sociopolitical relevance. It's about all sorts of things that matter to me, plus beautiful gut-wrenching explosions."

August 16: "Austenland"
In a summer filled with "gut-wrenching explosions," "Austenland" offers a respite for those looking for something more gentile. Keri Russell plays a mega-Jane Austen fan who spends her life's savings for a weekend getaway at a spot that promises to re-create life as portrayed in such classics as "Pride and Prejudice" and "Sense and Sensibility." She's hoping to find her own Mr. Darcy, but fantasy and reality collide in this comedy about role-playing romance, also featuring "Flight of the Conchords" star Bret McKenzie.

August 23: "The World's End"
Edgar Wright ("Shaun of the Dead," "Hot Fuzz") completes his Simon Pegg-Nick Frost trilogy with "The World's End." A group of friends (including Pegg, Frost, Martin Freeman, Paddy Considine and Eddie Marsan) want to re-create a classic pub crawl from their youth: 12 pubs in one night, ending at a pub called (what else?) the World's End. On the way, they discover that their hometown has been invaded by aliens! But that won't stop these determined drinkers. "We are going to get to the World's End if it kills us," Pegg vows. We'll probably die laughing.