From the list, I definitely pick "Richer"...
I'm not in the age that I wish myself to be younger...yet...
Thinner...something that can possibly work out by yourself
Smarter...能者多勞,no good.. OK...honestly, the smarter you are ...the more annoyed when you see how dumb other people are...
Younger, definately, and I am a guy. More time trumps all. Can probably get richer and or smarter using time, and I can potentially do a lot of other stuff with more time. Richer or smarter doesn't necassarily buy me time tho.