Define graphical style. If you mean how they're designed, I prefer actually the original Zelda the best. But based on how it looked in the games Manual. In essence, I think that's kind of the style they were going for with Wind Waker as well.
So I'd say the Original/Wind Waker style. Or, as they call it now, the 'Toon Link' style. I actually like the design for Toon Link in Minish Cap the best.











