Dragon Soul was the worst one in my opinion.
2 words. Dragon Soul. Enough said.
I'm the minister of mistakes. I'm the shaman of sh*tstorms. If there was a f**k-up pope. I'd have a 3 foot hat!
When arguing online I like to use big words. Because by the time they're done googling it, they have forgotten what their point was.
I would say Dragon Soul. Not because of the emptiness between Dragon Soul and Mists. Because Deathwing really didn't have an exciting battle, like for example The Lich king. I remember having fun when attempting Lich king, getting the strat right, etc. It was like, "omg finally!" after our first kill. Even after killing Arthas several times, even letting people get carried off to die on purpose, my guild still had a blast. We didn't get that with Deathwing.
As worst I would say was Mount Hyjal and then Dragon Soul.
It's fine IMO. There are many worse raids