If you guys are talking about bad sequels (well you were talking about transformers, but the thread took a side turn with the highlander-bashing)
then the absolute WORST, and I mean WORST sequel has got to be:
Anyone DARE to disagree?
I mean DANNY GLOVER? REALLY? Arnie, and a squad of the hardest men on the planet get knocked for six, and yet, old, burnt out glover manages to beat him.
ABSOLUTLEY THEE WORST.