Topping the list for Oklahoma is Chesapeake Energy Corp. at No. 18. Devon Energy Corp. ranked No. 28, American Fidelity Assurance is No. 47, and Tulsa-based QuikTrip came in at No. 66.

On the cover of the February issue of the magazine presenting the winners, Chesapeake’s logo appears on a picture of a briefcase alongside the likes of Google, Whole Foods Market, American Express and Starbucks.

This is Chesapeake’s fifth consecutive year on the list, and this time it jumped up 14 spots from 2011.

“While we celebrate any recognition of Chesapeake’s dynamic corporate culture, we are most proud of the people who work for this company,” said Aubrey McClendon, Chesapeake CEO in a prepared statement. “Our more-than-12,500 employees are what make Chesapeake a great place to work. Through teamwork and a commitment to quality and safety, the Chesapeake team is fueling a brighter energy future for our country.”

Some of the perks at Chesapeake added in 2011 include a 63,000-square-foot child development facility on the Oklahoma City campus. The energy company also reported it added two full-time chaplains available to all employees, and a comprehensive pregnancy wellness program for expectant mothers in all of the company’s operating areas. Incentives already in place include a $1,500 cash incentive to employees who practice healthy lifestyles. To further that effort, the company has a 72,000-square-foot fitness center.

Chesapeake reports in 2011 it hired about 4,800 employees. In 2012 it plans to hire about 5,000 employees in its operations around the country.

Devon also made the list for the fifth straight year. Last year, the company ranked No. 41. Among midsize companies, Devon ranks No. 12 on the Fortune list. It has 3,286 U.S. employees, and 5,000 including those in Canada.

“It’s our great people who make Devon a great place to work, so we see this as an honor for all of our 5,000 employees,” said John Richels, Devon president and CEO in a prepared statement. “Being named to the Fortune list for five years in a row is an outstanding achievement. It’s also a testament to our corporate culture, which is shaped by our values – including working as a team, doing the right thing and being a good neighbor.”

For the ninth consecutive year, American Fidelity made the list.

“I consider it a privilege to be part of the AFA family,” said Jeanette Rice, senior vice president of corporate and human resources in a prepared statement. “While culture is not the only factor guaranteeing our success, it clearly plays an unparalleled role. I know I’m not alone when I say it is truly an honor to be part of a workplace that not only makes a difference in our colleagues lives, but in the lives of our customers and our community.”

For QuikTrip, the convenience store chain fell from its ranking last year at No. 34 to No. 66 for 2012.