Please!! Hayden(Anakin) represents who will be the baddest and most feared dude in the Galactic Empire(Vader). He cannot possibly portray that and he didn't. Hayden Christiansen is way to winey and feminane to represent what will become Vader.
...which is precisely the point of the prequels showing the 'tragedy' of Darth Vader, is it not? Your rather sexist appraisal of Hayden aside, the whole point is that we never see who Vader 'really' is in the original trilogy...he is ruthless but eventually turns back to the light side before he dies. I think that is one aspect of the prequels that Lucas got right in theory and, like almost everything else in the prequels, failed miserably at in practice. That Vader did not come from this ruthless origin, but rather suffered a conflicted descent into the darkside, one in which he ended up destroying all that he loved and that loved him and was left with nothing but the Emperor and the darkside is an AMAZING idea. I think that having some macho d00d (like I'm sure we would all imagine yourself) playing Anakin would have been inappropriate. It is unfortunate that Lucas could not give his really great overarching storyline to someone with a bit more tact at writing/directing and watch it turn into more Star Wars magic. I'd imagine such greatness would have been lost on you anyways.