As Kurgan says Dooku doesnīt have "the Sith eyes" and if we admit that Dooku is the most elegant sith, he doesnīt fall in anger (at least he doesnīt show it). But all the other sith are very rude, they arenīt elegant, tehy use the dark side. Dooku looks like it goes trought it, he doesnīt let the dark side guide all his actions.
Maul is all anger and rude manners, the isnīt able of dominating the dark side like Dooku. And Vader itīs great, but itīs too much dark side. And, yes, I like Dooku a lot.
"Revenge is never a straight line. It's a forest. And like a forest it's easy to lose your way to get lost When engaged in combat, the vanquishing of thine enemy can be the warrior's only concern. This is the first and cardinal rule of combat. Suppress all human emotion and compassion. Kill whoever stands in thy way, even if that be Lord God, or Buddha himself..."