It is impossible to compare films by any objective measure because there is none (well maybe there is a budget/profit ratio which doesn't really help us here). Films are an art and they are completely up to individual opinion. By far the best reference we have are actually IMDb scores which are generalisation of large amount of opinions.

Looking at ROTJ score, it is at 75. place (within top 100 all-time). That pretty much tells you that people think it is a pretty damn great film. So if you say it is an average your opinion deviates considerably.

DominicCobb said:

Return of the King. And there are 11 guys named Oscar who can back me up on this one

Oscars are basically a generalisation of opinions of a few people. In that respect IMBd score is at least 1000 times more valid. Note that I am not arguing about ROTK greatness, I am just pointing out the worthlessness of Oscars.