As the Batman of the Marvel universe, it comes as no huge surprise that Iron Man is the man when it comes to outsmarting people. A potent mix of unreal tech skills, genuine tactical wit, and an ability to overprepare to every situation mean that Tony Stark is not only ready for any scenario, but he's also planned an intricate way to win it.
And while it's always interesting to see how he reacts when these plans fail, it's sometimes far more interesting to see what happens when they succeed, as his almost ludicrous plans - like mind wiping the whole planet, or rebooting a brain off of a floppy disk - channel all of the wonderful craziness of comics in the best possible way. Better yet, it generally doesn't feel out of character for Iron Man to carry any of this off, because - well, because he's Iron Man, so it's actually less weird the more elaborate his plans are.
With a not inconsiderable number of comics dedicated to showing Iron Man being dunked on by enough supervillains to start their own small colony, it's well worth exploring the times that Iron Man outsmarted everyone - to explain why he always looks so smug, if nothing else.
10. Fighting Jim Rhodes
Seeing Tony Stark totally outdo his replacement, Jim Rhodes - who is in Tony's suit, and who has significantly greater capabilities as a result of this - is one of the most masterfully executed fight scenes in the history of the character. Having the rightful Iron Man one-up a far stronger opponent sheerly because he knows the Iron Man suit so well is a genius way for the fight to go down, and shows that, even without the suit on, Tony is now and forever Iron Man at heart.
Add to this the fact that Stark had taken time off being Iron Man because of his issue with alcoholism, and him managing to outsmart his replacement is even more impressive. It suggests that, even when he's not at peak performance, Tony is still more than capable of outwitting even people who are significantly stronger than him.
Even better, we see Iron Man outsmart Rhodes one final time by showing him what the man couldn't see on his own - that Rhodes had become obsessive over the power and prestige that the role of Iron Man gave him, and needed to forgo his role as a hero in order to overcome his fixation.