Sooo hard to choose but i think Revan

Malthus with Revan and Nihilus tied for close second.

Seriously hard choice.

Without a doubt the hardest poll I've ever had to choose from. They all have their amazing feats and traits that make them likeable. here is a rough ranking..

No. 1 ) Darth Malgus and Revan

No. 2) Darth Nihilus

No. 3) Darth Sion

Therefore I can't vote at all.

Nihilus

Personal favorite is Darth Revan

Nihilus for his sheer presence and the sheer horror he embodies.

I acidentaly pressed Nihilus but i meant to vote for Malgus