I wouldn't call it the best episode overall (there's still the Crazy Ed stuff, and the pilot episode was very good- speaking of, loved that recap clip of the dentist's hilarious bitch scream) but Lights handing over the cash to The Rainmaker, then watching the big guy eat that address and icing his hand was definitely one of the best scenes they've ever done. It would even have worked without dialogue.
Morse was great. He's such a pro, one of those guys who can never be miscast. Liked the Ghost of Christmas Yet to Come (or given that this is FX, should that be Carl Weathers in The Shield?) vibe of his character. I also really liked Lights feeling some sense of responsibility about his friend's condition. One thing I think Lights Out does well is show that sense of camaraderie between guys who also happen to beat the living shit out of each other, how despite what the promoters would have you believe, in reality it's rarely personal.