It is me or it was totally horrible?
To me, the combination Claremont + Byrne was the quintessential and best X-Men cycle in history. However, Cockrum did a good job in #94-107, as well as #110.
I would say that anything in the #94-143 (and maybe even 144?) frame was the "CLASSIC" X-Men and pure perfection.
When Cockrum returned, well, it was super-awful. Bad stories and bad pencils. I'm sorry about this.