In Knights of the Old Republic 2, there is a dancer outfit (needed for some side quest), which is absolutely useless — except for giving some bonus to the Persuade skill.
The characters can go to confessionals in Tales of Hearts. At one point, Hisui admits he missed a shot because he was staring at Innes' breasts.
In Soul Calibur 4, you win either because you played with your eyes closed or you're already living a sexually satisfied life. If you win without these two, then you're probably a genderless robot or some other video-game-playing species entirely. Or happen to be disinterested in women while playing as Ivy. Or, y'know, both player characters are male. Though this trope doesn't always involve women being the distraction — Voldo is pretty damn hot.
The Sexy Nightwear apparel in Fallout: New Vegas gives a bonus to Charisma, which relates your Speech and Barter skills. Fallout 3 also has a unique "Naughty Nightwear", which gives greater boosts to these attributes, and also improves your character's luck.
This is actually an ability of Jessica in Dragon Quest VIII. Put skill points in her Sex Appeal and monsters will start missing turns just to ogle her. Her own allies, Chivalrous Pervert Angelo included, are immune. Dragon Quest IX has a similar effect through the "Style" stat, but it affects all playable characters and isn't limited to only sexy outfits.
Both games also feature active abilities to affect opponents in this fashion (learnable by both your characters and foes) - the Puff-Puff attack in DQ 8 and the Sultry Dance in DQ 9. Entertainingly, a foe that tries to use the former move on Jessica will get demoralized because Jessica is more voluptuous, and they miss a turn instead.
In Bayonetta, Luka wants revenge against the title (huh huh) protagonist. However, every time he meets her, he alternates between swearing revenge, and making clumsy, awkward sexual overtures. Presumably, it's kinda hard to remember what you were doing when you have... well, freaking Bayonetta standing in front of you.
Doubly invoked in this case when you remember that Bayonetta is technically naked! Her "clothes" is basically just her hair covering up her entire body, so in essence, Bayonetta gets that much more points for this trope
Final Fantasy IX: Zidane's head will move toward any attractive female NPC walking past him in a town.
Star Fox. Fox McCloud's first meeting face-to-face with Krystal sends him into a shock for a minute before Peppy's calling knocks him out of it.
Septerra Core. In the in-game mythology, Dogo the Trickster God convinces Gemma to give Kyra a mirror, so she could make herself more beautiful. Gemma does it, proving he forgot that she's his prisoner and can easily use the mirror to send messages to Marduk about her whereabouts, resulting in her rescue and Gemma's defeat. What part of the body this guy uses to thinks remains secret.
The Inazuma Eleven games have a pair of passive skills which invoke this, namely "Sexiness UP!" for females and "Handsomeness UP!" for males. Both decrease the success rate of nearbynote A player trying to steal the ball and the player he/she is trying to steal it from can affect each other, and any player attempting to shoot and the opposite team's goalkeeper can also affect each other. opposite-sex opponents' moves.
James: What the hell's up with EDI? Shepard: She's found a new home, I guess. James: A super-hot, sexy new home. You take her on a mission, I'm gonna be just a little distracted.
Additionally, if you're playing a female Shepard, the exchange becomes instead...
James: What the hell's up with EDI? Shepard: She's found a new home, I guess. James: A super-hot, sexy new home. You take her on a mission, I'm gonna be just a little distracted. (beat) (James's eyes wander downward) (beat) James: Even more distracted. Shepard: Nice try.
This trope appears again in the final single player DLC, Citadel- after escaping an assassination attempt, Shepard (who was at the time dressed up for dinner at a fancy restaurant) is finally found by their romantic interest, who spends a little time Eating the Eye Candy instead of focusing on the "people are trying to kill me" part. If your romantic interest isn't a full teammate in 3 or you haven't locked in your romance yet, it will be Liara, and she'll get the same line.
In Grandia, one boss is a giant angler-type fish with a lure that looks like an attractive female. The lure's only attack is Attract, which seductively draws Justin up towards it... then turns into a giant mouth and takes a bite out of him. The "distracted" part comes from the fact that this can cancel Justin's action if he's charging up a special attack or spell.
In Brain Dead 13, Fritz falls victim to this when he gets picked up by Vivi the sexy vampiress while Lance looks in confusion on what will happen to him... just seconds before she tosses Fritz into the spiked coffin! Ouch!
Not long after that, Vivi approaches and seduces Lance when he starts saying he wants to leave, and she starts turning him on for a bit... right before she stuffs his cap into his mouth!
This is actually a game mechanic in the Assassin's Creed series: hiring a group of courtesans/Romanies to either act as a mobile hiding spot or distract a targeted group of guards is an effective way of completing most of the stealth sequences.
This is used to solve a puzzle at one point in Fear Effect. Hana is caught by a guard and held at gunpoint. However, she's wearing only a towel, and the towel is a useable item. Use it, and she drops it. Deke proceeds to deal with the distracted guard. (Nice ass, Hana.)