I've recently re-watched the special editions. I think if I was going to make a set of Star Wars movies I would take the original New Hope, the updated Empire Strikes Back, and the original Return of the Jedi. Here's why:
New Hope: Lucas improved on alot of stuff, but like it's already been pointed out, the Greedo death scene ruined the experience. Everything else was great! From Han chasing the Storm troopers into a room filled with Storm troopers and having to retreat, to the new Death Star Explosion. However, because of that one Greedo scene I'll stick with the original New Hope.
Empire Strikes Back: The whole movie was great. The added creature footage (the eating of the tonton), the windows in Cloud City. It was all good, and I don't remember anything being taken out. I didn't like the Luke scream either, but it didn't kill the movie.
Return of the Jedi: HATED THIS VERSION!!!! I can't stand the fact that Lucas tore out original scenes in Jabas palace and inserted completely new characters. The new band singer sucked. I didn't like the Boba Fett flirting either. Unlike alot of people, I hated the end celebration. I liked the original ending, didn't think they needed to flash to every major planet and show celebrations. I could throw this movie out and wouldn't even miss it!
Just my humble, yet correct, opinion