You've got a little bit of time. Id stay somewhere in Rosemont, they all have shuttles. There are plenty of walkable restaurants, movie theater, outlet mall, outdoor areas to hang out.

Look at a map and see where the groups of hotels are. Most likely by the convention center which is a walkable area.

The Hyatt Regency is nice, but its not exactly located near that entertainment area.

Aloft, Hilton Rosemont, Double Tree or Embassy Suites would be better for walking distance.