Ron Rifkin is one of the greatest actors you can ever see. His portrayal of Arvin Sloane is absolutely wonderful.
He manages to make you hate the character yet feel symphaty towards him at the same time. Most of the times, one look at Rifkin's eyes can say more than 100 lines from a different actor. He showed mercy to nobody, except for a couple of people who were ready to kill him anytime, which is an incredibly complex relationship to act. He was perfectly cast, simply put. Alias season 2 was his absolutely best season.
It's kinda funny that while he was the ultimate villain, for the most of the show, he was a "good guy".
He's definitely one of the main reasons I loved Alias. And I'm glad to see that his career didn't end with Alias, but it carries on.