From what I've read, NTSC-M is the modern "global" version and came about around the time of DVD so that DVDs could be standardized. All flavors of NTSC are all inter-compatible, but each has it's idiosyncrasies and the NTSC-J is usually darker than NTSC-E (I think that's what the older US version was, but not sure.)
The reasoning is that NTSC had (has) flaws and extensions or fixes to the standard kept getting added. NTSC-M is a newer standard that takes all the various meddling with the base standard and incorporates the various enhancements.
It's a moot issue today unless you are dealing with the kind of stuff we are all trying to accomplish.
Usually though PAL is considered the best source as it has more resolution (just shy of 100 more lines) in the image. With LDs, take away most of the black bars and you have a small number of lines that need to be resized to make up the DVD image so the more that are there in the beginning, the better. PAL has more lines than NTSC so many people have chosen to grab PAL images (they also have no interlacing) and retime the video (slow it down) to 23.976 fps from 25. Assuming the frame count is standard and everything else is done properly, adding the correctly timed US audio should mesh perfectly.