I used to like Crusher better, mainly because Pulaski was mean to Data.
In retrospect I prefer Pulaski and wish they would have kept her, I think the only reason they didn't was because Diana Muldaur didn't want to sign on as a regular and wouldn't have been available for the first few episodes of season 3. What a stupid decision to let her go over that, they could have introduced a second recurring Doctor to fill in for Pulaski when Muldaur wasn't available or they could have simply not shown any Doctor at all for some episodes, it would have been perfectly fine, had their been missions where a Doctor was simply not necessary.
I liked her because
she was mean to Data!
Which I think was a plan from the start of the season that she would start to become a fan of Data by the end. She sure sticks up for him in Peak Performance.