My answers will be held in check as to not cause a spoiler, so here goes.

1) Top 3 that need to meet their end:
    Joffrey Baratheon...Justin Bieber personality on steroids.
    Tywin Lannister...This guy is overdue for some harsh poetic justice.
    Ramsey Bolton...I believe he really was Emperor Nero's bastard, and not Roose Bolton's.

2) Most likely to get caught with a "little finger" in a ponzi scheme: Peter Baelish...of course
     
3) Girlfriend I would most love to be with: Daenerys (Dany) Targaryen
    She's intelligent and has a big heart, not to mention her exotic spinner body with long  
    silver-blond hair and purple eyes. Delicious.            

4)  Most likely to make a good BDSM mistress: Lady Melisandre of Asshai (the Red Woman)
     Dripping hot candle wax on you is not even foreplay to the amount of heat she's gonna  
     bring.                                                                
                                                                         
5)  Most likely to make the best BDSM switch:  The Wildling woman Osha
     Even in shackles, she put Theon Greyjoy in his place using just her wits.

6)  Ultimate Underdog: Tyrion Lannister
     Lord Mormont remarks "You're a cunning man, Tyrion. We have need of men of your sort on the  
     wall." Tyrion grinned, "Then I shall scour the seven kingdoms for dwarfs and ship them all to  
     you, Lord Mormont."

7)  Woman that I'd most like to sail off into the sunset with:  Asha Greyjoy
     She probably has a strap-on tucked away in her nightstand for those times she wants to get  
     freaky, so I may be asking for trouble here...I can see myself being dropped off at the next port
     with my memoirs as her cabin boy, and a sore ass. LOL.

8)  Best Anti-hero and my favorite character bar none: Arya Stark  
     The little sister I would have loved to have as a sibling growing up, I can see her changing  
     engine oil or putting a wriggling worm on a hook with her bare hands.  I like her grit, as she is  
     determined and resolved as a seasoned warrior.  Arya's crafty way of turning the tables on the  
     "give me three names deal" with the assassin Jaqen H'ghar, in order to coerce him to help her
     free captives, is absolutely priceless.  I would be surprised and disappointed if Arya doesn't  
     do some major wreckage to a few of the bad guys in the remaining novels to come.

Good thread topic, I enjoyed thinking about it.