This quite a comprehensive list of delicacies accurately categorized by the states where they are locally made and are readily available. Special thing to notice is the delcacies actually blend with neighbour states. As in UP, Bihar & Jharkhand you will generally get all the dishes mentioned special to those places and that's natural.
I have stayed in Bihar & Maharashtra and so my local favorite dishes are Litti (Bihar), Pittha (Jharkhand) & Modak (Maharashtra). This classification is based on the picture above.