Here are some QOL ratings from a National Jurist magazine a little while back.
http://www.nxtbook.com/nxtbooks/cypress/nationaljurist1106/My notes are in italics. I only did research on some of the firms. You'll want to use
www.nalpdirectory.com to see if any of these I haven't noted have offices in Chicago.
Overall SatisfactionSedgwick Detert Moran & Arnold
(About 30 attorneys in Chicago office)Jenkens & Gilchrist
(no longer in business)Munger Tolles & Olson
Williams & Connolly
Carlton Fields
Manatt Phelps & Phillips
Saul Ewing
Hogan & Hartson
Fish & Richardson
Morrison & Foerster
For Lawyers with KidsArnold and Porter (DC)
Wilmer Hale (DC)
Paul Hastings (Atlanta, Costa Mesa, LA, Hong Kong, San Diego, San Francisco, Stamford, DC, Tokyo)
Gleary Gottlieb (DC)
Ropes and Gray (San Fran, Boston, DC)
Simpson Thacher (London, LA, Palo Alto)
Gibson Dunn & Crutcher (Dallas, Denver, LA, Orange County, Palo Alto, San Fran, DC)
HoursJenkens & Gilchrist
(no longer in business)Saul Ewing
Sedgwick Detert Moran & Arnold
(About 30 attorneys in Chicago office)Wiley Rein & Fielding
Munger Tolles & Olson
McGuire Woods
(About 150 attorneys in Chicago office)Shook Hardy & Bacon
Williams & Connolly
Thompson Hine
Winston and Strawn
(About 450 attorneys in Chicago office)Vault Top 20 QOL firms (2006 ranking). The 2007 data is out there somewhere, but the site is currently down.
Finnegan, Henderson, Farabow, Garrett & Dunner, L.L.P.
Morrison & Foerster LLP
Hogan & Hartson LLP
Dickstein Shapiro LLP
Cooley Godward LLP
Debevoise & Plimpton LLP
Jenkens & Gilchrist, PC
(no longer in business)Hughes Hubbard & Reed LLP
Manatt, Phelps & Phillips, LLP
Freshfields Bruckhaus Deringer
Ropes & Gray LLP
Latham & Watkins LLP
Munger, Tolles & Olson LLP
Winston & Strawn LLP
Sutherland Asbill & Brennan LLP
Irell & Manella LLP
McKee Nelson LLP
Davis Polk & Wardwell
Fish & Richardson P.C.
Weil, Gotshal & Manges LLP
Orrick, Herrington & Sutcliffe LLP
Vinson & Elkins L.L.P.