Not happy at your day job? Glassdoor Research—which recently found a correlation between staff job satisfaction and stock performance—announced the results of its 7th annual Employees' Choice Awards, which honors the companies its survey respondents voted as the best places to work. The 2015 lineup officially announced in December by Glassdoor lists the top 50 large and top 50 small-to-medium companies in both the U.S. and U.K. (Employee feedback at Glassdoor's Web poll site is still active, so some numbers may change after press time.) CNBC.com takes a look at the top 5 big firms at the head of the U.S. list. Brush up those résumés.

—By CNBC's Kenneth Kiesnoski
Posted 19 March 2015

Beantown-based business-services firm Boston Consulting Group's 4,800 consultants voted it into a fifth-place finish in this year's employee survey. BCG employees gave the firm 4.3 out of a possible 5 stars, according to the official Glassdoor tally. At last count, 90 percent said they'd recommend it as a workplace to a friend, and 98 percent signaled approval for the firm's president and CEO, Rich Lesser.

Employee quote: "A rocketship experience for a new grad—excellent vehicle for personal growth, surrounded by smart people."

Information technology company F5 Networks, headquartered in Seattle, was awarded 4.3 out of 5 stars by its workers. Ninety-two percent would tell friends to work there, and 99 percent approve of president, CEO and director John McAdam.

Employee quote: "Challenging, fun, the company actually helps you achieve your best."

Pet-food purveyor Nestlé Purina PetCare gets a paws-up from employees, garnering it a third-place finish and 4.4 out of 5 stars in Glassdoor's worker survey. Ninety-four percent would recommend the firm to a friend, and 100 percent think the world of top dog Joseph R. Sivewright, the company's new CEO as of 2015.

Employee quote: "Passionate, caring, hardworking, supportive people, making the best food for our best friends."

It may not be a household name, but consulting firm Bain & Company is tops with employees, snagging 4.4 out of 5 possible stars. That puts this Boston-based firm in second place in this year's survey. Ninety-six percent of employees would recommend a friend work there, and 99 percent approve of the job worldwide managing director Bob Bechek is doing.

Employee quote: "Fantastic people and company culture, with a reputation that will open many doors for you."

Where does Google not reign supreme? Perhaps unsurprisingly, the Mountain View, California-based tech behemoth came in first in Glassdoor's survey of best workplaces in 2015. According to Glassdoor, this is the first year Google came in at No. 1 in both the U.S. and the U.K. Workers gave it 4.5 out of 5 possible stars, with 94 percent willing to recommend a friend work there and 97 percent approving of co-founder and CEO Larry Page.

Employee quote: "Great balance between big-company security and fun, fast-moving projects."