Pros
I worked here as a contractor for 8 months in 2010. They are good to their contractors, paying well and being very flexible with work hours and time off. Grainger won a Chicago "Best Places to Work" award while I was here, and I can see why. I have never seen such happy employees at any company I have worked for. I would absolutely work for them again.
Cons
Long commute from the city. But they do provide a free shuttle from the Metra.