Not in order of importance and not considering 30th anniversary:
1) Leech: poor interpration and bad proportion
2) Snout Spout: poor interpration of the head
3) Dragon Blaster Skeletor: poor interpretation of the dragon head (no gimmick = no reason to disfigure head sculpt to make a vintage resembling sculpt)
4) Kobra Khan: bad interpretation of the head (no gimmick = no reason to disfigure head sculpt to make a vintage resembling sculpt)
5) Buzz-off: lame.