In Adventure Time, Finn comments after his first meeting with Flame Princess— who demonstrates that she is both literally and figuratively Hot-Blooded— "I think I have a crush!" Later, he gets very... excited... when he sees her beat up the Ice King.
(Watching Suki beat up a bunch of firebenders and capture the Warden.) Hakoda: "That's some girl!" Sokka: (smitten) "Tell me about it..."
Downplayed in Code Lyoko but Ulrich and William are both clearly attracted to Yumi at least in part because of her Action Girl status; she and Ulrich even had their first meeting at a martial arts class.
Zigzagged in The Dragon Prince. Callum falls in love with Rayla because she is kindhearted and has saved several people with her exploits. But if Rayla did not have her martial arts, she would not have been able to accomplish most of the deeds, because of that Callum fell in love with her.
Amazon: "Hello tiny man. You want sample small batch Amazonian maple syrup?" Fry: "Sure." (tries batch) "That's the kind of sap I like." Amazon: "You the kind of sap I like." Fry: "I'm scare-roused."
Generator Rex: While Dr. Holiday rarely throws down outside of her Mama Bear tendencies, there was a particularly epic moment she got where she saved Agent Six and Rex by rapid-firing at a huge monster, driving it back. Six's gobsmacked expression said it all.
Six: Wow. Rex: Yeah.
This also seemed to be the point where Six started returning Holiday's UST for him.
In Justice League, Wonder Woman may be one of the most powerful superheroes of all, and it apparently doesn't discourage most men lusting after her, including a DCAU version of Hugh Hefner. Even in a Time Travel story into The Wild West, the most significant reaction to her incredible power is from Bat Lash, a self-styled ladies man who notes admiringly, "That's a healthy gal!"
The Shade was noticeably pleased when he was picked up by Giganta when Gorilla Grodd invited him to be part of the Secret Society.
Giganta: The name's Giganta. Shade: Appropriate. Giganta: It's not a problem for you is it? Shade: Quite the opposite.
Kaeloo: Mr. Cat is much more attracted to Kaeloo when she's done Hulking Out, and on some occasions even seems to actually want her to beat him up.
Korra is a powerful bender and athlete. Bolin admires her because of this: "You're the smartest, funniest, toughest, buffest, talentedest, most incrediblest girl in the world!"
His brother, Mako, also seems to be this. Initially, Mako's totally smitten with Asami but he falls for her before he learns how tough she really is. This trope holds truer in his second girlfriend, Korra.
Korra and Asami could both be considered this, too, seeing as come the series' end, they're dating each other!
Texas might be this in Motorcity. He's shown a bit of a fondness for Kaia, as well as Julie after watching her fight robots in "Off the Rack." So far, he hasn't shown to chase any of the actual "Amazons" in the show.
In "Simple Ways", Trenderhoof becomes attracted to Applejack both for her simple farm life (which he considers refreshing since he's often surrounded by rich snobs), and her incredible strength. A jealous Rarity tries miserably to imitate Applejack, but can't get his attention. Applejack doesn't return his feelings, as his attempts to woo her make him seem like a stalker. And has some possible racial themes as he specifically points out being attracted to "the work ethic of earth ponies."
In "She's All Yak", Sandbar asks Yona to the Amity Ball and, while he never outright says it's because of her hulking yakness he makes it clear he prefers that over any of her attempts at coming off as delicate and high-classed.
Space Pirate Captain Hondo Ohnaka from Star Wars: The Clone Wars used to date Aurra Sing, one of the cruelest Bounty Hunters in the Galaxy, and even long after they broke up, he was very enthusiastic when he told her in her face what a dangerous woman she is. He also immedaitely tried to hit on Steela Gerrera, leader of the Onderon resistance fighters when they met in during a battle. Later he used a rather creepy, flirtous tone when talking to Ahsoka before and after he captured her, during his attempt to steal the lightsaber crystals of the Jedi Younglings she was protecting at the time.
Teen Titans: According to Robin, some of the things he likes the most about Starfire are "the way you shoot starbolts, ... that you're brave, and the strongest girl ever."