Emet-Selch & Hythlodaeus by miles. I'd trade every last Scion for those two. Hythlodaeus' speech in Elpis about his purpose being fulfilled by helping Azem and Emet realize their dreams and then the 3 will return to the star together... my heart. It made me realize that's something I don't feel the WoL has with the Scions. We're all just colleagues for the most part with shared experiences that doesn't necessarily equate to close friendships. Needless to say, having to part with my two BFFs in Ultima Thule to go hang out with my co-workers again... meh. :P