I loved New X-Men. The X-Men comics had been floundering for years and Morrison came along and gave them a good, hard kick up the arse! That first arc E is for Extinction is brilliant. Clearing the boards, jettisoning crap continuity and going back to basics. It was great, fun comics. The stories and characters actually felt like they mattered again, for the first time in years.
The series did go off the rails a bit towards the end. I loved the character of Xorn and wished Morrison had stuck with him a bit more. I loved the fact that Xaviers became a school again and there were all these punk mutants hanging around and rebelling against the X-Men's way of doing things. Lots of ideas being thrown at the wall to see what sticks. It's a shame Marvel got cold feet and essentially retconned everything once Morrison left.