Hey folks,
This is a great idea, but the requested format was airport/section of town/restaurant name. Let's get back to that so it's not a huge pain for the OP to organize or other folks to use.
ORD/Chicago City, River North/Rumba
They used to give miles every day, now there are no miles on Friday or Saturday. But the "Nuevo Latino cusine" is interesting and delicious, and it's a good place for a business lunch. At night (about 8, I think), they have a band that makes the in-demand booths pretty loud. The drinks are phenomenal, though pricey.
ORD/Chicago City, Loop, Downtown Area/Monk's Pub
Laid back (peanut shells on the floor at night) place to grab a great burger. Popular with downtown workers for lunch, at night it's people who live downtown getting dinner or office workers getting a drink after work. Definitely not fancy, but pretty inexpensive.