...or at least give you a double take, but either way if you dress up as any of these characters, you're sure to catch a woman or two's attention:
Cloud Strife
We'll start with the obvious. No one broods as much as Cloud, and apparently the the more you brood, the sexier you appear to the mass of squealing fan girls. The spikier your hair, the more fan girls you seem to get, either that or the longer and silkier your hair seems to be, creates the same effect. Either way, dress up as Cloud and you're bound to have a groupie or two. Warning: Dressing as Cloud attracts men as well, as he does appear rather effeminate. Another note: That sword totally compensates for what's lacking in the bedroom.
Squall Leonhart
Continuing with the Final Fantasy theme Squall is pretty much the same as Cloud, only his world is completely based around dropping acid by the time it hits the 3rd disc. His defining characteristic that summons the hordes of banshees screeching his name? The facial scar. Sure he accidentally got it during a "training accident" with his rival Seifer, but it still looks pretty badass. With a scar that noticeably plastered across your face, any outlandish tale would be perfectly believable and would totally reel in the ladies.
Riku
Pretty much anything from Kingdom Hearts is a dog whistle for the ladies, but Riku pretty much takes the cake for being the biggest attention whore of the whole game. I mean, the game's about Sora and I guess sometimes Roxas, but whenever Riku has screen time it suddenly ends up being all about him and how important he is, even though he loses to practically everyone in the damn game. But that's alright, because fan girls know to look past a guy's personality and focus on the most important thing, and that's appearance. Why I recommend Riku over Roxas or Axel? Axels come in armies. The last thing you want to be is the 10th Axel down the line. Then again, assassins exist for a reason.
Ezio Auditore da Firenze
And on the topic of assassins we move to dear Ezio. You could strut around with your charming Italian accent or merely stalk and leap of faith atop your prey and hope they accept you. If they refuse, simply kill them, hide them in a haystack, and be on your way. If you are unable to perform any of the above you have no right to dress as Ezio and I will personally find you and end your life myself. If you can complete these tasks efficiently my address is...
Hatake Kakashi
Here's another obvious one. It's guaranteed you'll either be knocked out by a blunt object, dragged into a hotel room by a flock of fan girls and raped repeatedly, or continuously glomped and tackled until you fall unconscious, to which you will be dragged into a hotel room and raped repeatedly by a group of possibly not fan girls.
Link
Women can't resist men in chain mail, especially the ones who we assume to be of the chivalrous kind, because you're frickin' Link. The more detailed and heavy your clothing and equipment appear, the more you'll be picked up by the female radar. Don't forget to pack your Master Sword and Hylian shield, because without both you'll just look like Peter Pan. Girls don't flock to Peter Pan.
Vash the Stampede
My one recommendation? Wear platform shoes. Apparently the more ridiculously tall you look in this costume, the more bad ass you'll seem. That red coat is super frickin' long for a reason, why not use all of it? Once again, Vash falls under the "spikier your hair is, the more fan girls you obtain" scenario, so make sure your spikes are as stiff and high as possible and you basically got the ladies in the bag.
Leon S. Kennedy
Personally, Chris Redfield is far hotter than Leon, but for some reason Leon has the majority of the fan base wanting to grab his ass. Which is fine, because then I can have more Sir Redfield for myself. Once again, the more of the brooding/I-don't-give-a-fuck type you are, the larger your fan girl base. I would describe Leon as having a permanent stick lodged up his ass (then again who wouldn't when zombies are involved?), but something about his hairstyle just reads as "emo-kid," which translates to "attractive to women."
Wolverine (Hugh Jackman version)
Lastly I bring you Wolverine, the Hugh Jackman version. I say this, because anyone who has ever dressed up as the accurate-to-the-comics Wolverine gets the handshake and their picture taken. Anyone who opts for the blue jeans topped off with a wife beater and dog-tags gets dry humped. The more you look like Hugh Jackman, the higher your chances of that evolving into something less public...maybe.
And there you have it. I'm sure there are more I haven't brought up, but these seem to be the most popular and the most likely to be found in a back alley and raped.