Even though PTA and the actors think the scene feels like it's from a different movie, my vote still have to go with the Donut shop and "the Christmas." In retrospect, my subconscious said "so THIS is why everyone loves this movie!" during and after that scene. It has comedy, action, sadness (I think when the clerk gets shot it's pretty fuckin' sad) and a sense of hope all in one. Not to mention Christmas and all that 70's plastic.
My Vote: Donut Shop, Boogie Nights.
Sydney- Jimmy and Sydney in the car. "it fucks up the retail value!" and the way PBH goes "Mm-hm" without changing his facial expression.
Magnolia- Nothing stands out, but I really like Guzman with "That's not a rule? Oh that's a fuckin RULE!"