Didn't see anyone mention Chicago, so I'll go. The city itself has instituted quite a lot of new bike lanes and even bike-specific traffic signals downtown. It very much feels like bike culture is taken a firm hold, at least downtown and on the North Side. In the suburbs it's more spotty. Arterial roads can be harrowing to travel on, but the good news is that you really can get just about anywhere with a little bit of planning by taking side streets. I would put the majority of drivers as "bike-neutral". They aren't hostile to cyclists, but they aren't especially courteous. Being the midwest, there is a smaller but significant contingent of drivers who are actively friendly, especially toward families. Riding with my wife and son, people often wave us ahead at intersections and make a point of waiting patiently for a safe moment to pass.

I ride through the West Side on my commute when I bike all the way in, and that's a different story. I can't count the number of near-doorings, right hooks, people blindly exiting parking lots, children dashing madly into busy streets (I actually have very good reflexes which has saved me from running over multiple kids), etc. If you're going to ride on the west side, bring your defensive cycling in full or else.