In the Batman: The Brave and the Bold episode "Night of the Huntress!", Blue Beetle is distracted by Huntress's sex appeal instead of having his head in the game during the fights:
Blue Beetle: I'm sorry! Your hotness distracted me!!
Hilariously used during an episode of The Boondocks, when Tom draws the attention of a prison inmate.
When Paulina on Danny Phantom was first introduced, they showed all sorts guys reacting to her like this. Oddly enough, that's the only time they did.
At one point in Dexter's Laboratory, Dexter gets so fed up with Dee Dee, he holds interviews to get a replacement. He winds up hiring a vixen who he can't do any work around.
In the Disney ClassicTMBen and Me — the story of how Benjamin Franklin owes all his inventions and wisdom to a mouse — ol' lecherous Ben is ogling a young woman when the mouse yells out "Post, Ben! Post!" leading Ben to comment "Well, how do you do, Mr. Post?" shortly before smacking face-first into said post.
Truth in Television; Mr. Franklin had an eye for the ladies.
Happen in Welsh Stopmotion show Fireman Sam when Trevor Evans crashes a bus in "Dilys's Forgetful Day", when he drives past Penny, the new girl in the Ponypandy fire service.
This is done mostly every time Amy Wong is wearing less than usual.
In Bender's Game, during the parody of The Lord of the Rings, one orc-thing climbing a ladder while assaulting the castle catch sight of Amy taking off her top through a window. Cue abundant drooling, which happens to be acidic and burns through the ladder's steps, sending him falling.
Invoked by Mickey Mouse in the House of Mouse episode "Clarabelle's Big Secret" when he attempts to prevent Clarabelle Cow from revealing the secret by distracting her with Horace Horsecollar, who is in his underwear while striking a manly pose.
The Mask has a perfect example of this (though it can also count as Show Some Leg, depending on how you look at it) in the episode "Flight as a Feather". After stripping two suicide belts off an exotic dancer named Cookie BaBoom (who crashed a ceremony held by the Mayor), The Mask sees Kellaway and Doyle coming to get him. The Mask then gets behind Cookie (who has been trapped in her own whirling dervish) and stops her so that way the front part of her naked body faces Kellaway and Doyle. The Mask escapes, Kellaway and Doyle melt like a Hershey's kiss on a hot skillet, and the Mayor smiles as he basks in the glow of his ex-girlfriend's humiliation. And this was all on a CHILDREN'S show (albeit one from the 1990s, when this kind of shock humor was in vogue).
Believe it or not, Mr. Bogus, of all people, actually falls victim to this in the episode "Bogus Private Eye", with a female rat who enters his office to tell him about the crime organization that had arisen in the city.
In the Phineas and Ferb episode "I Scream, You Scream", Ferb's initial encounter with his Precocious Crush, Vanessa, leads to him taking the plans she was picking up and vice-versa.
Phineas: Hey Ferb, snap out of it! What happened back there? Ferb:...I was weak.
Large zig-zag: On The Powerpuff Girls in the debut episode of the Rowdyruff Boys, the seemingly defeated girls get some advice from Ms. Bellum in turning the tide. The girls completely disarm the boys with long, come-hither eyelashes, then they make the boys explode by kissing them.
Regular Show has four instances of Mordecai reacting to seeing Margaret in various outfits and slightly sexual situations:
"Caffeinated Concert Tickets" gives us him immadiately cutting off his sentence and drooling when he sees Margaret in a shirt which shows some generous Sideboob.
"Mordecai and the Rigbys" has him gawking with his mouth gaping open and dropping the box he was holding when Margaret puts on one of his band's shirts (a bit hard to explain, here's a clip. Unfortunately it's in Spanish as all the English versions get removed).
In "Do or Diaper", Mordecai freezes for a moment and stares at Margaret in a fancy dress after she opens her apartment's door when he comes to pick her up.
In Rick and Morty, "Interdimensional Cable 2: Tempting Fate", alien doctors need Jerry's penis in order to save an old ruler. When Beth is given a catalog of prosthetic penises to choose from, she reads it like a Playgirl magazine.
Jerry: Hi, honey, so, here's the thing... these guys... they want to completely remove my penis and use it as an alien's heart. And we just need you to sign off on it.
Jerry: (to the Alien Doctors) Uh-oh. Maybe we got a problem here after all, guys. Yikes.
Alien Doctor: (to Beth) His penis will be replaced with a sophisticated prosthetic. Now, there's a wide range of options to choose from. They're all in this catalog. (gives Beth the catalog)
Beth: I don't care about prosthetics. This is insane. What do you people think you're doing?
Alien Doctor: I understand your feelings, Mrs. Smith.
Beth: Oh, I don't think you do. I-I bring my husband in for emergency treatment, he's gone an hour, and now you want his penis, (opens catalog) and you hand me some... catalog. (sees catalog's contents)It's-it's-it's-it's-I mean...
Angelica:(referring to Ms. Lion) Well, somebody's found a friend. Peter: You can say that again! Angelica: Her name is Ms. Lion. I'm Angelica. Peter: You sure are... I'm Peter Piper... Uh, P-Parker... Uh, Parker Peter—
In "Omens Part One", the first time Lion-O meets his Body Guard Crush Cheetara his voice cracks. Lion-O later feigns this, using the sight of two passing women to avoid mentioning a vision he saw in the Sword of Omens.
In "Journey to the Tower of Omens" Lion-O, trying to master Sight Beyond Sight and failing, gets flustered when Cheetara tries a Hands-On Approach, taking him by the shoulders and telling him to relax.
In the same episode, Tygra openly gapes at the sight of Cheetara using her Super Speed, which Panthro lampshades with a smirk and a chiding:
Played straight when Heather's top is ripped off and it distracts Harold during one of the challenges.
Also Alejandro shirtless in World Tour.
Totally Spies!: Used as a background gag in Season One's "Wild Style" once as a couple of guys walk into each other due to being focused on Sam.
"The Suavest Spy" is an episode where the spies have a mission to watch a charming and attractive jewel thief and they just always get distracted while doing that due to his good looks, and taken even further when him and Clover dance at a ball, he's also stealing the key to the world's most valuable jewel using Clover's gadget, yet she doesn't even notice due to being too excited to dance with him.
This particular gag returns much later in Season 6's "Trent Goes Wild". A girl walks into a tree because she was too busy staring at a hotter version of the titular Trent (pictured above).
Happens during Blackarachnia's first appearance in Transformers Animated. As soon as it is revealed that the giant, scary-looking alien spider is a giant, sexy-looking alien robot, Bulkhead and Bumblebee (who have apparently never seen a female of their species before) immediately drop their guard, which allows her to take them out.
Six from Tripping the Rift. Practically anything she does will make a guy's jaw hit the floor.
In an episode of X-Men: Evolution, the X-Men are repairing their mansion. Scott Summers and Jean Grey distract each other. Jean almost smacks Storm with a statue she was levitating. Logan angrily orders Scott to pay attention.
In the Steven Universe episode "Hit the Diamond", RubyandSapphire suffer a mutual version of this. It especially effects Sapphire, who can literally look into the future to see where the ball will be, and her team still almost loses because she's too busy flirting with Ruby, who has infiltrated the opposing team to throw the match.