(1) Copy Boy: The disassembled pieces of an Amazo/Super-Adaptoid robot were being transported by truck to whatever the SHIELD equivalent is in that universe. The Hydra equivalent attempted to hijack the truck, things went horribly wrong and Our Hero was at ground zero when the bits exploded. Powers: Touch-mimic of super-powers. He can keep powers as long as he wants, but once he drops one power to make room for another, it's gone. Eventually, he'll be able to keep powers long term, when he has enough XP to fund the permanent powers. Drawbacks: Mimics are a bookkeeping nightmare, and are a pain for the GM and player.
(2) USAngel: An amalgamation of SHAZAM and Captain America. Chosen by Uncle Sam (the Spirit of America, who appears as a vision only Our Hero can see), he transforms into a winged super-hero when he says "We The People." (and back by saying "E Pluribus Unum") Powers: Flying brick, plus a small variable power pool for skills & languages with the not-really-a-limitation that he's accessing the skills of some American citizen. Drawbacks: Not a lot of room for growth, just shoring up holes that weren't purchased at character creation.
(3) The Jedi Knight: Our Hero was cosplaying as a Jedi at some con, when some sort of reality storm happened and he gained all the powers of a Jedi. Had some legal battle with Lucasfilm, that eventually gets settled (though he's got a handler DNPC). Powers: The Force & a functional light-saber. Drawbacks: Light-sabers are killing attacks, which makes him not really willing to use his most powerful weapon because he doesn't want to lop people's arms off.
(4) Kestrel: During the first generation of modern supers, The Hooded Hawk and his teenage sidekick Kestrel fought crime. The Hawk eventually had to retire, but Kestrel kept on fighting. Over the years, a sort of "Batman Incorporated" thing developed, with multiple Kestrels around the country operating independently but under a shadowy organization. Powers: the physical skills of Batman, with an Oracle-esque hacker providing intel and tech support. Drawbacks: Batman is expensive.
(5) The Big Man: So when super-heroes with growth powers get bigger, they get stronger. But what if, with all that extra brain matter, they got smarter too. He can grow pretty big and serves as a brick in combat, but he's also a skill monkey with all the Knowledge skills he can take. He normally stays at 10' tall because any smaller and he feels like an idiot. Powers: growth/brick powers, with a linked intelligence boost to go with the strength boost. Disadvantages: Giant characters sometimes get screwed by their size.
(6) Metal Master: A ferro-kinetic. He doesn't manipulate magnetic fields, but he can shape metal with his mind. Essentially a young Magneto who can't set off EMPs. Powers: can mold metal with his brain. Disadvantages: Nothing comes to mind.
(7) The Enforcer: Stolen from Crisis at Crusader Citadel and Burn Notice. Our Hero was a spy, but got burned due to getting force-field powers, and there's some sort of international treaty that prohibits metas from acting as spies. So he decided to put on a mask and fight crime. Powers: force field manipulation plus martial arts training and guns. (That can shoot mercy bullets.) Disadvantages: Nothing comes to mind.
(8) Clockwork: Our Hero is a time-manipulation-based speedster. Sure he can get across town in the blink of an eye, but he's exhausted because he doesn't have any sort of super-endurance. Powers: temporal acceleration and deceleration. Disadvantages: Champions makes it hard to do power stunts that aren't exactly paid for.
(9) The Envoy: A little bit Hercules, a little bit Aquaman from Brave and the Bold. He's an alien prince, sent to Earth to seek Adventure so that when he has completed his mission, he could take his throne. Powers: Brick. Disadvantages: Nothing comes to mind.
(10) Comrade Atlantis: In the 1960s, a Communist conspiracy overthrew the monarchy of Atlantis. Now it's a communist country, and Our Hero is a diplomat who has gone more or less native. Fighting crime was originally an accident, but he decided to keep fighting crimes because it's fun. Powers: aquatic brick with diplomatic immunity. Disadvantages: Might be too jokey of a character.