Of all the official releases of the OT, which ones do you like the most for their color grading? I often find when watching a release I havent seen before, the grading is what often has the biggest part in whether I like it or not. If for some reason you don’t like the entire set of films in one release, then pick for each individual film.
Going off of 35mm scans I’ve seen and certain aspects of the home releases on VHS and Laserdisc, my personal favorite is all three of the 1997 Special Editions. For as controversial as they may be (not to mention despised), I think they do a good job of giving the films an updated and vibrant color grade that still has the spirit of the original grading. Best of all, the blacks aren’t crushed into submission.