Kansas City does not cross any state borders. There is a Kansas City, KS and a Kansas City, MO - they are completely different cities and both are in only one state. If you mean to say that the metro area is what's in multiple states, then Providence, RI should be included (the metro area extends into Massachusetts).
Indeed, I am from that area and its so crazy that on one side of the street was 4.5% sales tax and TN side it was 10%.. Bristol is a nice city though too.