Definitely not Delta and not AA unless you want to fly in one of their crappy MD-80 s or similar, so I d suggest taking United. They d probably have the best service on that route anyways since United is based out of Chicago. They usually use the newer embraer planes that are very comfortable.AA and Delta are only good for international long-haul travel. United is fairly good with their domestic service.
United. I fly them everywhere. AA has those noisy MD 80 s which are so antiquated you wonder if you will make it to your destination in one piece. United, I believe has the most nonstop flights from Chicago to anywhere in the world.
I travel UNITED bi-weekly from Laguardia Airport in Queens NYC to O hare in Chicago. United is ok. Sometimes there are delays but nothing over 45 minutes. I ve been doing this commute for the past year now without incident.
I like United best and then Delta. American makes their seats too narrow and therefore you spend the whole flight with someone in your lap.