<< Looking at the list - i think Waves 3 & 4 are really extremely obscure>>
Luke--
I have to totally disagree with you here. Waves 3 & 4 include ROWLF! SCOOTER! JANICE! SAM THE EAGLE! ZOOT! SWEDISH CHEF! These are big, MAJOR characters. Rowlf and Scooter were in Muppet Babies so everyone remembers them, Zoot and especially Janice are quite well-remembered, and the Swedish Chef is among the *most* popular of all Muppets. From where I'm standing, Series 3 and 4 are LOADED!
I think Series 5 is where we hit a snag. Rizzo is my favorite Muppet, but the fact that he has to be THE big Muppet in that series seems a bit much to me... I think Series 5 could be the one that kills the line. I would've much preferred if Statler Waldorf were kept in to give it some extra star-power...