The ultmate way to say something/someone is the coolest there is. Someone who is suave is so radically cool, that the words cool, swell, sweet or chill can't even begin to apply. Can also be used in the place of hot when speaking of a really really hot young woman. But its not gender specific.
The word suave in this usage has its origins in Vancouver BC, Canada by a radically suave group.
Yo man, that sports car of yours is really suave!
Dude, did you see that babe? She was so totally suave!
Yo babygirl, your style is real suave!