I never had a problem with ESB. I never felt it was particularly dark or whatever. It was a cool Star Wars film with cool locations and Darth Vader. I think I always liked it slightly more than the first one, but the Yoda training Luke part bored me and that part still does a bit. Originally ROTJ was my favorite Star Wars film (after I saw it in 83 that is). Now I like it about equal with the first film, a bit behind ESB.
Re when I first saw the films:
I totally loved Bespin and Hoth and the Star Destroyers. I didn't really get the Han and Leia romance. I thought it was a bit silly. But I liked both characters a lot, though Luke was my favorite back then.
Tatooine made a big impression on me too, and the Mos Eisley cantina. And the invasion of the rebel blockade runner in the beginning of the first film, with the stormtroopers and Vader strangling the captain.
When ROTJ came around I was a bit older and I took it in slightly differently, but I loved it. There was all this anticipation leading up to ROTJ. I still love ROTJ, though my feelings about the Ewoks are a bit more mixed. ROTJ was MY Star Wars film, the way the others weren't, because I was a Star Wars fan for years before I saw it and I experienced all the lead-up and anticipation before it came out. I loved the Luke storyline in it and Vader's redemption (I was a big Vader fan) and the old unmasked Vader we met at the end. I loved the Jabba section of the film and I still do. I loved the way ROTJ was a triumphant film -they beat the crap out of Jabba and his goons, then they beat the crap out of the Emperor and the Empire, and Luke and Vader came out of it shining (though Vader was a tad dead). I suspect that if ROTJ was less triumphant and more downery it might get more respect.
1983 is a long time ago now. 26 years. People have grown up and had kids who weren't born when ROTJ came out.
And it was great when ROTJ came out. It was like a big celebration.