ANH
Liked:
1) The shots of Ben's hut and the Outrider.
2) The improved shots of the Rebel force heading for the Death Star.
3) Inserting the Biggs scene at Yavin.
4) Fixing the cell block length.
Disliked:
1) Greedo shooting first (self-explanatory)
2) Introducing the Millennium Falcon by having Jabba and his goons surrounding it. It really feels in the OUT like you're seeing things from Luke's perspective, and following him around and being awed by this massive freighter that's practically invincible. It gives the Falcon a greater presence, in my opinion.
3) Mos Eisley is a "hive of scum and villainy", not a hive of repair droids and Jawas acting slapstick on Rontos.
4) Having Han run into a crowded Stormtrooper room complete with Tie Fighter. (Look, he's getting shot at by MANY Stormtroopers! KOMEDY!!!!)
ESB
Liked:
1) Showing the Bespin residents being warned by Lando of the Imperials.
2) The improved visual effects.
Disliked:
1) Luke's scream while falling down the shaft in Cloud City. (Why scream if you're voluntarily dropping down the shaft???)
2) The "improved" Emperor scene. (Stupid, adds more continuity issues, and makes Vader look like a putz.)
3) Adding more of the Wampa. (It's scarier when you DON'T see the whole creature! Build UP the suspense!)
4) Vader going to his Star Destroyer. (Do we REALLY need to see this? It's unnecessary padding.)
ROTJ
Liked:
1) Most of the Celebration scenes at the end.
Disliked:
1) The Naboo Celebration scene. (Unneeded, forced, and just plain stupid.)
2) Anakin as a Force ghost. (Makes no sense whatsoever.)
3) New song in Jabba's Palace. (Stupid and clumsy attempt to show off the latest CG.)