lol, I use emoticons for the same purpose.
When people think of iconic Star Wars, they think of all three movies. Force ghosts, ewoks (not actually referred to as such within the movie,) the Emperor and his guards, the rancor, Jabba, speeder bikes, the sarlacc, A-Wings, Admiral Ackbar - all classic designs. I think the influence of Lucas is a little bit apparent, but overall it's still one of my favorite movies and the rest of the cast and crew pulled it out of the fire. Even people who hate ROTJ still usually love all of the things taking place in space with the battle and the confrontation between Luke, Vader, and the Emperor. When I watched it as a kid, it was my favorite because it had all the cool aesthetics, music, limb-severing and stuff from the other films, and it was funny in a way I could understand. As kitschy as it was, "bad" humor with puppets is better than any humor with Prequel CGI.
I think it's an Act I, Act II, Act III kind of thing. Of course Empire is the darkest, which is why you need a return (heh) to the adventure and fun. It's the same reason the Dark Knight Rises and The Last Crusade are great movies that wrap things up tonally, and sometimes edge out as my favorites of their respective threes.