A couple of thoughts on this issue.
First, if you are in-state for either UIUC or Michigan, they are an obvious choice over Northwestern for engineering.
Second, rankings you see are dominated by the research reputation of the departments, and are not aligned much with quality of undergrad education. I would say that either of these three schools will prepare you very well for engineering design kind of jobs.
In looking at placement information, do consider the fact that Northwestern has much smaller engineering student population (about 400 per year, as compared to nearly 1600 for each of UIUC and Michigan). Electrical engineering at Northwestern is actually very small - around 20 students per year or so … see
I think advantages of Northwestern are in better faculty to student ratio, more emphasis on undergraduate education, and in recruiting from consulting/finance side. Both Michigan and UIUC will provide you with excellent technical preparation and the degree will be highly weighed by engineering recruiters.