I personally like GIGAMINING and YABMC because I know the guys running them but there are many to choose from.
I, on the other hand, personally like Cognitive and Synergy, because I'm fairly acquainted with the guy running those.
I heard that guy never needs to sleep. And that he's half man, half bear, half pig.
Yes, I am a zombie manbearpig. Actually some sleep might be beneficial right now