Gotta go with the Cataclysm method. No RNG being a huge deciding factor, but effort. I guess this is somewhat the same with WoTLK, but I like Dragonwrath most out of all legendaries. Withholding the fact that sometimes, a few less "mats" (like the Val'anyr fragments or Shadowfrost shards) would drop.
TBC must be the worst to me. Warglaives and Thori'dal don't feel special at all, as it's only based on luck and not on effort.