For me, syntax is one of the top priorities because if I can't express what I want using something compatible with how I think, then it doesn't matter if the language has SuperLib 4000 available if I can't program with it.

Personally, the opposite is true for me - case in point: python.

I really dislike both the semantics and syntax of python. However, the scientific computing libraries (pandas, numpy, scipy, scikit-learn, matplotlib, seaborn, etc) are just too productive to turn away from for quick data analysis tasks. If these libraries didn't exist, I wouldn't touch python with a 500-foot pole.