I'm like most here, Northwestern & Michigan State.
Northwestern: Mostly the obvious reasons, the prestige of the school, appear to do things the right way and have their priorities in order. Have always liked Fitz. Their fans seem to enjoy the victories rather than be angry with the defeats.
Michigan State: Always have liked them, have always liked & appreciated the way Izzo coaches, same with Dantonio now. Always looked down upon by their arrogant rival. All the MSU fans that I've met seem to be the same way as Northwestern in that they enjoy the victories and relish them.
Pretty indifferent to Illinois, Purdue, & Indiana. I used to like Penn State and still did even in the face of the scandal because one or two guys doesn't make for an entire university, but I may not like them much longer with Franklin there. I wasn't bothered by OSU when Tressel was there, but they're easy to hate now with Meyer. I dislike Iowa less than Wisconsin; I've had bad experiences with them but also some decent times with them.
The state of Wisconsin can be sold to Russia for all I care......