#2 Michael Cole's heel turn

When Daniel Bryan joined WWE in 2010, Michael Cole was not a happy man.
Lambasting the future YES! Man for being a vegan and not owning a TV, Cole would become a huge fan of The Miz, Bryan's NXT pro who similarly loathed the indie star.
This eventually became a fully-fledged heel character for Cole, and though heel commentators weren't new (Jerry Lawler, Paul Heyman etc), this was something different.
Cole was supposed to be the play-by-play guy, and his constant heel antics, including unrelenting digs at his fellow commentators, made listening near-impossible.
It got even worse when the former war correspondent entered a feud with Jerry Lawler, bringing up The King's recently deceased mother.
Somehow ending up in a match together at WrestleMania 27, the cherry on top is that Cole would accidentally win via disqualification.