Well for years, ROTJ (the first one I ever saw, in theaters, of course), WAS Star Wars for me. It was a simple story about some a group of friends looked out for each other during this galactic civil war. Luke is this thoughtful young Jedi coming to terms with the fact that his father is an evil Lord, and having courage to face the Emperor even though everybody else is giving him different advice (kill Vader, he's past saving). Leia is his sister. Han Solo got himself in trouble and doesn't understand what's going on... he's the eternal skeptic until the end. Lando isn't much good on the ground, but he's a great pilot. Luke is mad at Obi-Wan for saying Vader killed his father instead of telling him the truth. Anakin was once a good man. The Ewoks are primitive but their superstition is turned to the good of the rebels.
The Emperor STEALS THE FRICKING SHOW every time he's on screen. He's either sinister and slow like some creepy old man, or he's cackling like a maniac with those weird reptilian eyes. He's got the force too, whoa! So many quotable lines from this guy... it's no wonder Lucas decided to make the Prequels about him. Too bad he wasn't quite so entertaining there (especially since everyone around him acted like an idiot).
It seemed like a pretty self contained story to me back then. I knew there were other movies, but I hasn't seen them. I saw Star Wars next and Empire last. For me, it was all about the monsters and aliens back then.
I never heard that people hated the ewoks until I was a teenager. For me, I thought Yoda was more annoying in ESB (seriously), and C3PO was annoying in ESB. Though as I got older I saw the Yoda stuff as funny. The Gungan stuff in Episode I was far, far worse (at least people told him to shut up!).
To me as a kid what struck me about the Ewoks was not "boy these Imperial troops suck, it's so unfair that they go out this lame way," rather it was "boy the Ewoks have weak weapons but they're really smart and creative, which makes up for it." I remember how they tried all those tricks to take down a walker (ropes, rocks, glider, etc) which didn't work, so they had to resort to the giant logs, and then Chewie helped them steal a walker. Then you see an Ewok with a blaster. It's like they're adapting and learning. That was cool to me as a kid. I never thought of them as teddys, ironically. When I first saw the Jawas I wondered if they were related (I still maintain this theory... just listen, they have the same battle cry!).
The saber battle is shorter than in ESB, but man... you can sense the rage in Luke as he just WAILS away at Vader, no finesse, just sheer hatred... like how dare you say that about my sister, bam. Vader was so evil and suddenly even he is taken by surprise. Though when Vader puts up one hand at the end it's so pathetic, like he's using his last ounce of strength just to put up a token effort. Was that him or just his robotic hand obeying its programming? Anyway. I also love the solid WHAM sounds the sabers make when they hit, they sound so HEAVY and powerful. In the other movies they don't sound so amazing. The prequel sabers sounded like whiffle bats in comparison. You feel like getting hit by one of these things would utterly destroy you (too bad earlier in the movie it just seems to burn right through you with no dismemberment). Was Luke's saber too sharp or not sharp enough?
LOVED the space battle. Yes, ANH has the suspense and individual dog fighting. ROTJ has the sheer spectacle... and yet you can follow it (unlike say the Prequel fights, which are just a mess of images, or else they have to stop everything to focus on one pilot, usually leaving his ship to do something else). I liked the sense that the Empire knew they were just toying with the Rebels. I loved Jabba, his booming voice especially. He and his crew were just scum, they didn't care as long as they could have a drink and a smoke while watching somebody get killed by some big monster. I was always shocked as a kid that even the Gammorean guard who falls into the pit with Luke gets jeered at, like they don't care about even their own guys. Despite all that, I was sad when Jabba died. Blowing up the sail barge seemed like overkill. Wasn't everybody dead by then? I guess that's how you finish off gangsters, leave no trace!
So I think it depends upon how you first experienced them. I wasn't born early enough to have seen the other two in theaters, though I do remember a few minutes of ANH (my dad reading me the Greedo subtitles in the theater) so I'm thinking I probably saw it at some triple bill or something (and missed ESB completely for dinner or something). I didn't see ESB until I was in grade school on video (wow, this new fangled VHS!).
Over time I came to appreciate the others, especially ANH, which for me as a kid was the "most boring" because it took forever to get started.
By the time the Special Editions rolled around, I still didn't know ANH well enough yet to notice all the changes (I blinked and missed it when Greedo shot first, noticing the crowd gasping more than anything). It was really the special editions and all the analysis that got me to really "know" the films more. So ironically, it was the ruination of the films that made me really appreciate the minor details. But ROTJ is still my favorite, even if the characters are "enriched" now. Still, not knowing the other movies erased some of the conflicts in the storyline for me. Vader was always Luke's father, and Leia was always his sister. Luke was always a Jedi, and Obi-Wan always lied to Luke to try to achieve the greater purpose for the galaxy (Luke would never have tried to kill his own father). There was enough suggested by this movie that I could fill in the blanks in my mind. Yoda was old and dying now, but he trained up Luke before that (the student was returning to his old teacher), and so forth. Obi-Wan was a ghost, so I presumed he'd died already, like Yoda (until I eventually saw the scene of Vader killing him and figured out the rest).
ROTJ was a big part of my childhood, now that I think about it. I view it differently than I did then, but I can still recall a lot of what I felt in those days watching it, over and over and over...