If you could become...

[Satsuki]

...the main character of any anime, which would you choose? Any character classified as "main" in the story is okay. The events of the anime don't have to play out exactly the same if you became the character, you'd make your own decisions and such.

For badassness:
Accelerator - Toaru Majutsu no Index

For lots of beautiful women and sex:
Rito Yuuki - To Love Ru
or
Ichika Orimura - Infinite Stratos

 

[Captain Cadaver]

Sakata Gintoki - Gintama

Either that or *insert harem mc here*.

 

[Event Horizon]

Goku for pure power
Takuro Hayami for sex

 

[Pyro]

Kai Hiwatari from Beyblade comes to mind first. Only I wouldn't lose to Tyson, and I wouldn't be used as the guy to hype the main villain's strength so Tyson could come in and win and take all the glory (seriously, I never liked how despite being a TEAM tournament, Tyson was always referred to as "the" world champ after season 1).

Oh, and of course Seto Kaiba from Yu-Gi-Oh!. I can't pass that up. Being rich beyond reason, having broken cards in a universe that doesn't shun broken cards, and having a cool white coat? Badass. The only downside would be rescuing Mokuba each season.

 

[Let's Go Fearless!]

Ranma for being cool. That way I can have a lot of enemies!

 

[Son Gokū]

"There's no one I'd rather be, than me."

 

[Arcadya]

Alphonse Elric/FMA - Dat FMA alchemy looks too fun. Would have picked Ed, but... well... no alchemy. I wouldn't be a dick and not make the trade.

Tsukune Lastname/Rosario + Vampire - Fell out of the series, but he had become pretty badass when I was reading it last. Plus there's that sweet harem.

 

[Kyo]

Natsu from Fairy Tail. That universe has hot chicks, magic seems fun, and I would never lose because I fight for muh nakama.