Well, there's pretty much no difference between the Rayearth sets. They're even the same identical disks in the box, just the packaging is different. I own all three US DVD releases, since it's one of my favorite series of all time, and can verify that the disks in the most recent set are the exact same as the ones from the first.
You'd probably want the "World of Rayearth" set, since it includes both seasons in a pretty small box for a good price. The two "Economy Boxes" are just the two seasons separately, and the individual disks are still available, but the original box sets are out of print (a pity, since the Season 2 box is one of the nicest I've seen).------------
Honou Productions
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Honou Productions.
You'd probably want the "World of Rayearth" set, since it includes both seasons in a pretty small box for a good price. The two "Economy Boxes" are just the two seasons separately, and the individual disks are still available, but the original box sets are out of print (a pity, since the Season 2 box is one of the nicest I've seen).------------
Honou Productions
------------
Honou Productions.