which one of this would make a better-to-watch duel?

Mace would annihilate Vader. His strokes weren't wild power strokes like Vader's; they were simply to the point.

also dooku vs. maul.
But i would like dooku vs mace more.

Yeah that would be a great battle too. Mace definitely knows how to use a lightsaber. And dooku knows how to hit and run.

Dooku knew he couldn't take Yoda so he took a coward's way out by running.

Exactly what im saying.

Not at all. Dooku was holding off Yoda just fine. With completely different styles, each fighter was expertly countering every move made by his opponent. Dooku's priority, though, was escape- enemy forces were in pursuit. That duel would have otherwise gone on forever and Padme and co would have turned up and captured him.

Smart, but still a wimp!

I still say he was a coward and that remains my steadfast opinion. Your opinions are obviously different and I respect that. I ask for the same in return.

We all want a little respect.

If Dooku would have stayed and finished the fight, Yoda would have taken him apart.

Of course.