4 Sheldon Good & Company International

Headquarters: Chicago

Top Executive: Steven L. Good, chairman & CEO

Contact info: 800-962-0931

www.sheldongood.com

5 Williams & Williams Worldwide Real Estate Auction

Headquarters: Tulsa, Okla.

Top Executive: Dean C. Williams, chairman & CEO

Contact info: 800-801-8003

www.williamsauction.com