To be honest, both of the versions aren't perfect, but overall I prefer Sebastian Shaw. However, Shaw is just some random old dude who we've never seen before (don't tell me about how we saw him as Vader in the unmasking, I couldn't tell who the hell that was), and Shaw looks nothing like Anakin (who's supposed to look about 20 years younger).

But Hayden's is also bad, because when he's supposed to look at Obi Wan, he looks at his feet. (?) The ideal scene to me would be Hayden with an "older" haircut (not some pretty boy haircut), and actually LOOK at Obi Wan while actually being part of the scene.