Congrats on your offers! It seems like the three depts are similarly appealing to you research-wise at this stage, so, if I were you, I’d focus on the quality of life for a PhD student in each dept. What are the funding packages at each dept? What do these become when adjusted for the cost of living in each city? What are the RA/TA responsibilities associated with each offer?
More generally, what college/city environment would you perform best in as a PhD student? When you visited, did students seem happier at one university than another/is the attrition rate lower at one dept than another, etc?