It's pretty much everything about tehm that I hate (apart from the some of the designs and the effects which I have to admit are rather good). A lot of it is down to personal taste rather than anything else but I think the dialogue for the most part is clunky and cliched, the acting is fairly appaling (with the exception of Carrie Fisher and Harrison Ford who both seem to be phoning in their performances but still act everyone else off the screens), the stories are generally pretty dull for action adventure films and the directing is plodding at best.
Now I should say I've onyl seen a few minutes of the new ones but they seemed even worse than the original three if anything. Even the designs aren't up to the ones in the first three and the effects are laid on with a trowel seemingly only because there is mroe they could do with them this time. The first three just bore me (we went to see one of them when the re-released them ten years ago or whenever it was and I fell asleep halfway through because I was so bored). I don't feel any emotional involvement with any of the characters and it feels like they could have squished all three films into one and maybe just about had a decent story rather than lots of the same thign done on different planets with different terrains.
C3-P0 and Luke are two of the most annoying characters ever brought to screen, apart from Vadr all the villains are pretty dull, the whole ewoks beating technologically advanced Stormtroopers is stupid in the extreme (even given the whole 'they knwo the terrain better' arguement) and generally they're full of plot holes that you could drive a truck through.
The odd thing is I can sort of vaguely see why people like them. I also can't deny the impact that they've had ont eh way that films are made (especially sci-fi and big budget action adventure films). At then end of the day though I think Lucas is one of the most unbelievably over-reated film makers ever and the films themselves aren't classics by any standards in my book.
not that i like to rant about it or anything....