Reel New York 10–10:30pm, WNET Channel 13. We don’t need a documentary about Grey Gardens to tell us how great Albert and David Maysles’s 1975 masterpiece is, but here’s just such a film. Liliana Greenfield-Sanders chronicles her obsession with Big and Little Edie with an avalanche of clips that make you want to pop in the DVD instead of listening to people talk about it. Still, a terrific interview with Albert Maysles justifies enduring Greenfield-Sanders’s self-indulgent Edie Jr. playacting.