City annexation should be something that is done wholesale all throughout Cook County. We have more municipal governments than any other state save for PA. That includes states like CA, TX & FL that have a much higher population than us.
One thing we can quickly and easily do is eliminate townships which are basically a relic of a bygone era.
Within the Chicago metro area, especially Cook County, suburbs under a certain population threshold should either be annexed by the city or amalgamate with one another. No need for thousands of different taxing bodies (school districts, fire protection districts, police districts, library districts, mosquito abatement districts, etc. etc.). They can merge and become more efficient as a result.
My dream would be all inner (and slightly less inner) suburbs within the 294 belt get annexed by the city. That should net us at least two million new residents. Should helps us keep Houston at bay for another century or so
Of course, anyone who proposes this will face immediate political suicide, so its never going to happen.