I agree too, that the sabers in the PT are more elegant, but it makes sense- those were the sabers at the height of the Jedi Order, where everything was a lot more... "ornate". I don't know how better do describe it, other than look at the Jedi temple, the Jedi Council chambers, the Senate hall; everything was"grand" and you really got a sense that THIS was the height of the republic, and the sabers had to match that.
The OT sabers however, are a lot more run down; just like the rest of the galaxy, as Aayla said above me. It all fits in, there were few materials to maintain and build new sabers, so all those involved had to "make do" with what they had. And besides, in those war torn desperate times, they probarbly had no time for ornate-ness ;)