Someone posted a valid argument for ironman (which many neglect to respect), so i'll try to make a valid argument for thor.
I'd say thor wins because, unlike ironman's battles with hulk, thor is a lot faster and more agile than hulk.
Thor is faster and more agile than ironman, and has hell of a lot more fighting skill (thousands of years of training). Iron man may have a few surprises for the thunder god, but thor has lots of other weapons too.
there's the god force blast, and there's lightning, teleportation,blizzards, storms, and other magics of thor.
plus if thor gets seriously hit, he may get knocked down but he can grit his teeth against the pain and continue to fight.... unlike if ironman gets seriously hit, and his armor is damaged, he may have a lot harder time on fighting.
i also think that thor is more durable than tony's armor. just my opinion tho.