Both Thor and the Vision are two of the strongest heavy-hitters on the current roster of the Avengers, but should the two ever come to blows, which superhero would come out on top? The God of Thunder and the most advanced synethezoid on the planet frequently work together, and the latter can even lift the former's legendary hammer Mjolnir in the 2015 film Avengers: Age of Ultron. But if the two ever met in battle, there would indeed be a decisive victor.
It must be noted that while the Marvel Cinematic Universe versions of each character are quite powerful (especially when comparing them to their teammates such as Iron Man and Captain America), both Thor and Vision are far more powerful in the comics. A situation similar to the first Avengers film in which Thor was easily overwhelmed by a small handful of Chitauri soldiers would never happen in the comics. The comic version of Thor is far more powerful.
As the son of Odin and Frigga, Thor is a full-blooded Asgardian, and like all Asgardians, is incredibly strong, durable and long-lived (an Asgardian who has lived for a century is considered young, as many live for thousands of years). He can punch enemies into space, can crumble mountains, and can lift an entire skyscraper on his back - and with Mjolnir, he can shatter entire moons if he deems it necessary (not to mention call down lightning from the sky). He has fought against the Hulk, the Juggernaut, and Hyperion in hand-to-hand combat (Hyperion, considered to be Marvel's version of Superman, has more or less equivalent strength). His stamina and durability are truly legendary; he can go without sleep for months, survive in space, and most human poisons don't affect him; he has even defeated a Giant in a drinking contest.
The Vision is quite strong as well - he can rip straight through a mutant-hunting Sentinel's armor - but not nearly as strong as Thor. The Vision's only hope in winning this battle rests with his unique ability to control his body's density. Thor's attacks can phase through him - but Vision cannot maintain a phase state forever (and of course cannot win if he only stays on the defensive. Even if Mjolnir was taken away from him, Thor is many times faster and stronger. If Vision attempts his standard move - phasing through an opponent and becoming solid - it's more than likely Thor will just rip through his opponent.
Thor is a God of Thunder; while not the Creator of the Universe, he has all the power that the title suggests. Vision, as advanced as he is, has very little hope of achieving victory in this fight even with Mjolnir, and if Thor was truly angry and could not be stopped by any other teammate, the Vision would be ripped to pieces in short order. Just as well, then, that both Thor and the Vision are on the same side.