Affiliation : One of the founding members and leader of The Justice League Of America
Background : Cast away from the impending doom on his planet Kryptonite, he crash landed on planet Earth ( much like Dragonball Z fame Goku) and has been living there since. In his teens he finally got the hang of his awesome superpowers and chose to use them to protect earth from the wrath of the villains. He dawned his trademark suit so as to avoid being identified which was designed by his foster mother Martha Kent. He is the leader of the Justice League by his own right and protects the Earth from treacherous villains like Doomsday , Braniac and his biggest foe Lex Luthor.
Affiliation : The Avengers
Background : Thor is the Norse God of Lightning and is the son of Odin , the ruler of Asgard. Being banished after defying his father he comes and falls in love with Jane Foster. Being robbed of his mighty hammer Mjolnir Thor loses all power and becomes the common man Donald Blake. Even after learning humility Thor refuses to go back to Asgard and makes Midgard (Earth) his home. He joins the Avengers and has on several occasions saved them from aliens, his brother Loki and other frost and fire giants.
LET THE FIGHT BEGIN!!!!
Skill : This is going to be tough. Thor doesn't get to use his Mjollnir which is his main source of power. He has seldom fought without Mjollnir and once when he was stripped off Mjollnir he became as good as a commoner living as Donald Blake. Of course then he had lost much more than the hammer, but let us get to the point.
Thor is the strongest of the Asgardian and has a belt of strength which gives him superhuman power. Though he is a god he isn't immortal, like all gods of Asgard he relies on the Golden Apples Of Idunn to sustain his lifespan. he has also performed several feats such as lifting the 'World Serpent' which encircles the Earth and throwing the heavy Odinsword through a Celestial. Like all Norse Gods he has the capability to enter into "Warrior's Madness" ( commonly referred to in games as Berserk mode).
Owing to his superior defense - Superman wins this round by besting Thor.
Thor - 80/100
Superman - 90/100
Intellect :
Superman has shown some fierce mental capabilities over the years. He has many a times been shown to read all the books of the entire library in less than 5 minutes. He has alos defeated his pet robot in super-chess who could think and process a million moves per second.
Thor on the other hand being an Asgardian holds knowledge of facts that a mortal or even a Kryptonian can only dream about. He is also able to move about in all the nine realms housed inside the Yggdrasil. However being a Norse God Thor is ofen shown to have tremendous rage and over-confidence. He was sent to Earth by his father to learn the power of humility. He can be seen as a DragonballZ Vegeta, the one who is adored but also the one who is arrogant.
Superman wins this round over Thor as he first gauges his opponent before charging him, which is unlike Thor.
Thor - 65/100
Superman - 75/100
Armour :
Superman's armour is nothing great it is made of cloth and is a body-hugging blue jumpsuit with a red cape and underwear. Not that he needed one though, his body density prevents any harm to him and the jumpsuit and cape enhance his speed and agility.
Thor on the other hand wears mystical chainmail, high boots , red cape and a winged helm. All were forged of Asgardian steel which considerably more durable and tougher than Earth Steel. This is also the reason he isn't harmed by earth's military forces.
Thor obviously wins the bout with his superior armour
Thor - 80/100
Superman - 60/100
Special Abilities :
Now comparing Superman's Heat Vision to Thor's Mjollnir. While Heat Vision has severely adverse effects on even the toughest of the metals , it will be very interesting to see if Thor's Mjollnir can nullify the effect. Thor's Mjollnir has often seen to parry the most unlikely blows and plus he can also muster the lightning against the heat vision.
Overall I guess Thor will destroy Superman in this round as Superman is known to be weak against magic (remember Darkseid's attacks) and Thor's Mjollnir can actually be more effective with its versatality though if he loses his hammer that will mean his end.
Thor - 95/100
Superman - 85/100
RESULT
Thor - 320/400
Superman - 310/100
A hard fought battle but the Thunderer ousts the Man Of Steel due to the magical Mjollnir made of the rarest uru metal. Avengers take victory as the Justice League leader is kept at bay.