"Figata" means something cool, awesome (questo film è una figata!)
"Figo" is more for people: Quel ragazzo è proprio figo (it means for instance that he dress very smart, well.
"Figa" we use less, since it means "cunt".
Anyway, "figata" is a bit old fashioned today, I would use more "bomba" or, in juvenile jargon, "sballo" (sballo also means to be high on drugs).
Questo film è veramente uno sballo, troppo bello!
Questo libro è propio una bomba, contiene un sacco di informazioni utili.
"Figo" we still use, mostly in the negative sense: quel tizio si crede tanto figo, ma non lo è...
Be careful we do not use "figata" and "figo" just like "cool", as you see the use is sometimes different and never in formal conversation. Also Spanish people say "guay" a lot, but again we use it differently and more sparsely.