Well again we come back to the Emporer, he was defeated by Mace, Lucaas said that the Emporer did not give up he was simply defeated. Also in Attack of the Clones you see him easily blocking so many blaster shots, even when not looking or when jumping down from that platform he simply deflects them away. That right there shows his skill with a Lightsaber is unequaled.
As far as Anakin, he is not even that strong, so he slaughtered a bunch of padawan's and children in the Academy, ooooh. Obi-Wan says that he has become much stronger since the last time they met in ANH, which I doubt the Emporer let Vadar become any stronger. Obi-Wan beat him the first time and could of done it the 2nd time, but it wasn't his destiny, he was old and the Jedi order was meant to be remade.