Gladiator king of the Shi'ar and all around badass. The Thor guy is Beta Ray Bill.
To expand a bit, from wiki:
Gladiator possesses a number of superhuman capabilities as a result of his unique alien physiology including superhuman strength (capable of shattering a planet), superhuman speed, stamina and durability (capable of withstanding an explosion equivalent to a supernova); reflexes; heat vision (stated as "hotter than a star");frost breath and is capable of warp speed flight (measured as "a hundred times the speed of light"). Gladiator's abilities increase and decrease in accordance with his level of confidence and he is vulnerable to a certain form of rare radiation.
That's right. Not only can he kick just about anybody's ass from the jump, but the more he knows he can kick your ass, the stronger he gets.
Beta Ray Bill, aka "horse Thor", is actually a genetically engineered alien champion who, in his first appearance, kicked Thor's ass and took his hammer. That's right, he was the first person other than Thor to be worthy of lifting Mjolnir. Then he and Thor had a fight to determine who was more worthy to wield the hammer. Beta Ray Bill won.
He gave Thor his hammer back, JUST BECAUSE HE WAS A NICE FUCKIN GUY, and Odin himself was like "holy crap dude, you kick ass!" and then made Beta Ray Bill his OWN hammer that's JUST AS GOOD AS THOR'S AND IS CALLED "STORMBREAKER". How badass is that shit?