Episode Title: "Members Only" (Season 6, Episode 1)
This one might seem contradictory, given the previously cited "flaw." But while—from a verisimilitude standpoint—it would only make sense that Tony would retaliate against Uncle Junior for the assassination attempt he orchestrated on his life in season one, viewers were glad he didn't. As it gave them five more seasons of Dominic Chianese's hilariously cantankerous capo, who just happened to utter some of the series best one-liners.
Unfortunately, the show did not like to let their elder characters ride off into the sunset gracefully; like Tony's mom before him, Junior develops dementia, eventually shooting Tony when he mistakes him for an old (and long-deceased) nemesis and ends up living out the rest of the series in a mental institution. Leaving viewers devoid of any further "Junior-isms." Boo!