I've honestly seen every wave, except 7 and 3, in good quantity here... I saw Wave 7 too, but it was a lot of remnants mostly. Wave 3 was the only wave I'd say was a bit tougher to track down.
Wave 4, 5, and 6, all saw heavy distribution here, especially at WM (though 5 made the rounds at Target a lot)... they almost all would sell, but that's why all those ROTS Clones are around where I'm at. The ROTS Wave didn't deposit the majority of them, but rather most seemed to come from the repacks actually.
Stuff sold fast though... Definitely a "blink and you may miss it" situation with any given case that got put out. A case here, a case there, then poof gone... Only the pegwarmers remaining, none of the new stuff. Gradually now it's gotten to where 4, 5, and 6 all move slower now. 3 and 7 are the only waves that really have much life to move at the moment, and 9 of course if it hits.