If you could have any skill

[deus-ex-machina]

ive always wanted to be a master linguist, in theory i could go to any country and fit in.

Pretty much this. I'd love to be able to persuade people to do what I want too.

 

[Queen Michael]

Being a great singer. Or possibly writer.

 

[Bazamm]

If i could have any ability in the world, i would chose to have perfect skills of deduction. That way, i could see what i have to say to get out of any hole i've dug myself, and see the right way to haggle prices down.

 

[joshuaayt]

I'd take the entire art of Ninjutsu, thanks. Or at least some of the 18 sub-skills WIkipedia mentions as part of it. Maybe Kenjutsu and Intonjutsu.
It would be weird, having the skills but not the muscle. Guess I'd have fun trying to use them to bulk up, and end up damaging myself.

 

[crudus]

giving a rats ass. I could definitely go for that skill.