The Hybrid Cut by TM2YC is currently the best way to go with THX 1138. TM2YC focused on trying to use as much HD footage from the blu-ray as possible, while keeping the film cut to match the laserdisc. Only new effects that genuinely looked better were used, otherwise it’s the original effects. The footage cut for the blu-ray is from the Laserdisc and is not great quality, but this is something like 9 mins of the entire film, and it works quite well.

In terms of cuts of THX, there were actually 4 different cuts. The one most people call the original cut is actually the first reissue of the film. The actual original theatrical edit has never made it to home video. WB cut footage from the film for it’s first theatrical run, and George added it back after it’s post Star Wars rerelease. The other cut is the German and Italian version that’s only slightly rearranged and trimmed, but not super noticeably. I don’t think it’s known why though.