How Iron Man Would Defeat Every Justice League Member
6. Wonder Woman
In terms of abilities, Wonder Woman is likely the closest Justice Leaguer to Captain America, with a splash of Thor thrown in for good measure.
Both the Amazon and the Sentinel of Liberty have superhuman strength and endurance, both are master strategists and leaders, and both are pretty darn tough to kill. Whilst tough to kill, though, both Diana and Cap have indeed perished over the years in the comics. Of course, comic books being comic books, said demises haven't exactly remained a permanent arrangement.
Still, the point stands that it is possible to get the better of Wonder Woman.
Pulling a page from Batman's playbook in the opinion-splitting Tower of Babel storyline, Tony could use Diana's own will to win against her. Forever up for a good fight, Wonder Woman simply cannot say no to battle. As detailed by the Dark Knight when compiling records on how to defeat each of his Justice League cohorts should they ever go rogue, the best way to stop the Lady of Justice would be to trap her in a simulation based around continuous combat.
Given Iron Man's intelligence and resources, he could easily put together just such a machine to trick Wonder Woman into an endless fight with herself.