My Go-to For Biz Travel in Chicago
I travel to Chicago often, and bounced around hotels looking for the right one for me, and totally found it at River North - the lobby is great, with just the right amount of buzz with the open bar/restaurant right in the middle (though not overly trendy like at the W). The rooms are great, clean, modern and comfortable. The Staff are friendly and very helpful. It does seem sometimes that the bell staff push hard for tips, which can be awkward, especially if you tip during pick up, not drop off. This isn't a deal killer however. 
It's close enough to downtown to walk across the river bridge to your meetings in the morning, and to the subway for a quick ride to the airport, but more importantly, it's right where the happening night life is - restaurant row, bars, movies, house of blues, you name it - if you walk AWAY from the river (ask the concierge) you walk into the best of Chicago afterhours. The hotel is a great spot to meet friends, colleagues and clients before heading off to a great dinner.