So there are plenty of characters to choose from and they all have their shitty and redeeming qualities which are your favorites?
I love Dean, I think he's a rock when everyone needs it even if he isn't always unwavering.
I love Crowley, while a total and complete backstabbing asshole he is an amazing character overall and I think that his attachment to his life is an interesting aspect of him. It makes him selfish but also vulnerable.
Last but not least, I love Loki. Yes I'm going to still call him Loki even though you find out that's not who he really is. He's just fun and always hilarious no matter when I see him.