Even though I was 10 when ROTJ came out, I didn't see it (or ESB) until I was 13 years old, which would have been 1986. I grew up in a pretty strict Baptist household and my parents didn't allow us to go to movie theaters until the mid-80s. I didn't see ANH until its television premiere in February 1984.
So I knew the entire story behind the Star Wars trilogy before seeing any of the films and that might have changed my perceptions a bit. I remember still being totally blown away by ANH when I first saw it. When we finally saw ESB and ROTJ, it was at my cousin's fiance's house and we watched both films on VHS back to back. I might have been a little let down by ESB as well, but I think my overall reaction was more positive than my initial impression of ROTJ. However, after 6 years of anticipation for ESB and 3 years of anticipation for ROTJ, I'm not sure if any movie could have lived up to that... except for ANH which still impressed me after 7 years of anticipation.
That's probably why ANH is the measuring stick by which I grade every movie even today.