D'Artagnan thinks very highly of his dueling skills. First he challenges three men to three duels, all in the same day. Later he tries to take Athos on in a drinking game. You gotta admit, the kid's got moxy!
D'Artagnan: Athos, why don't you come join us? Athos: You fight like a man. See if you can drink like one. D'Artagnan: I'll drink anything you put in front of me. Athos: Famous last words...
Porthos is such a Badass that he takes the time to enjoy the "finer things". Right as he and the other Musketeers and D'Artagnan are escaping from the Cardinal's men, in his own coach!
Porthos: Champagne? Athos: We're in the middle of a chase, Porthos. Porthos: Hmm, you're right... something red.
This next bit during a chase, in the coach is more like a Crowning Moment of Funny, but it still shows that Porthos is awesome!
Porthos: For a chase, the Cardinal recommends his excellent '24 Cabernet. Porthos: (to D'Artagnan) You can't have any, you're too young.
Porthos seems to be a walking example of total awesomeness. When he's not being the goofball for the group anyway.
Villain: It's Porthos the Pirate! AAAAAHHH!!! (All of the bad guys jump overboard) D'Artagnan: Pirate? Porthos: I told you I was famous.
Aramis, the Badass Preacher gets a really good moment near the end of the movie, when everyone thinks he's dead. He's unconscious after being shot at by the Cardinal, and Porthos tries to revive him.
Athos: Is he dead? Porthos moves the crucifix round Aramis' neck, revealing it stopped the bullet, and Aramis regains consciousness. Aramis: See? There is a God.
Even the King gets one during the climax, when he punches out Cardinal Richelieu (who for a moment received a smug Hope Spot when it seemed the king was sparing his life).
Athos continues to try and save the king and kills a good chunk of the Cardinal's men using his non-dominant left hand. Why? Because his right hand was stabbed earlier.
As the final three musketeers face down the entire army of the Cardinal's, it becomes clear why they look so confident when it's revealed that they've convinced all the other musketeers to come out of retirement.