They seem to be the easiest. There's always individual outlier stores that prevent it, but on the whole they're the most consistent. I've also been able to use Bed Bath and Beyond GC for Disney and other 3rd party cards. But not all BBB's carry 3rd party gift cards, and some BBB's have store policies that prevent it (or poorly informed staff that foul it up) even though the POS system allows it. So unless you shop at lot at Bed Bath and Beyond, Buy Buy Baby, or Harmon Face Values and can use them on regular purchases might be easier to stick with the majors you listed.