I worked as an usher in a theatre when Star Wars came out. I watched that thing 6 or 8 of times a week during it's 6 month run. It really is a good movie, although C3-PO gets really fucking annoying after the second month. The acting isn't that good (Alec Guinness excepted) but as a whole everything comes together well and it deserves it's reputation. TESB was better as the acting had improved and it had a darker and more adult tone. An aside, why does Jabba the slug monster surround himself with scantily clad humans, that's some perverse bestiality stuff (ewwww). Then we got a decent conclusion to the story marred by teddy bears with stone spears defeating armoured storm-troopers armed with blasters (sigh).
I do love the LOTR trilogy and all three are equally strong IMO but I do see your point comparing the 1st 2nd and 3rd instalments. I couldn't make it through The Hobbit, when I find myself hitting fast-forward every 10 minutes I just give up