Happy employees = successful companies. It’s just kind of how it works.

Research shows that when workers are happier, they’re more likely to work to their highest capacities, get high performance grades, and give the company a competitive edge.

So what makes a happy worker? Things like a good office environment, good managers, flexibility, camaraderie, and then of course, the work and the salary (though salary usually isn’t as important to us as we think).

Some companies house much happier employees than others—and the careers site CareerBliss surveyed thousands of employed people to see which companies ranked the highest for happiness. They asked them questions that rated different factors that contributed to their happiness—things related to their relationship with management, the workplace environment, compensation, satisfaction with job function, and growth opportunities.

Behold, the top 20 happiest companies in America (see CareerBliss’ full list of the top 50 here.)

1. Keller Williams Realty

   While the average salary is only $50,000 (lower than some of the others that scored less happy), Keller Williams, the largest real estate company across the globe, scored big points for CEO approval. With an overall happiness score of 4.3 out of 5, they’re the number one happiest company for the year.

2. Nike

   The average salary for Nike employees is $40,000, but a total of 87 Nike employees gave Nike an average happiness rating of 4.1 out of 5, giving them the number two spot on the list. Perhaps they also get reduced-price merchandise—we think that would make us pretty happy!

3. Total Quality Logistics

   The third largest freight brokerage firm in the country, Total Quality Logistics employees make an average of around $74K and had a really high average happiness rating: 4.4! It seems that management styles vary greatly, but they still totaled a 97 percent CEO approval.

4. Adobe Systems Incorporated

   This computer software company values employees who are “genuinely, exceptional, innovative, and involved,” they say. They really want the best for their employees: growth, work-life balance, healthy living—which is probably why they rated a 4.1/5 for overall happiness.

5. Amgen

   This biotechnology company employees 17,500 people, and, while the management scored an 83 percent (lower than its predecessors), they have a 4.1 happiness rating and a $75,000 average salary.

6. Chevron Corporation

   One of six major oil and gas companies in America, Chevron is the 16th largest company in the world—and comes in at the sixth happiest companies in America (that’s a lot of sixes!). Employees love the challenging environment, growth opportunities, and quality management.

7. Intuit

   One employee said it best in a review: “This is by far the best place I have ever worked and I have told many people that I will do whatever it takes to stay here.” This software company is located in California and employees can’t get enough (that average salary of 82,000 might help too!).

8. Bristol-Myers Squibb

   Though their CEO approval is at a 67 percent, employees gave this biopharmaceutical corporation a 4.3/5 for overall bliss. Employees get three weeks of vacation to start with, and can earn up to three weeks more—maybe that helped a bit!

9. PNC Financial Services Group

   A top employer for the financial services industry, the company says its proud of their “well-educated, competent staff.” With a enjoys competitive salary, top-notch benefits, and tons of other perks and programs, PNC employees gave their jobs an overall happiness score of 4.3.

10. TruGreen

    As the nation’s largest lawn care company, the average salary is just $33,000, but they’re still in the top 10 happiest companies. We’re thinking it’s due to their commitment to making others happy by providing “a beautiful lawn to serve as the foundation for outside experiences and lifelong memories,” they say.

11. CIGNA

    This Connecticut-based health company makes sure to put the well-being and satisfaction of its employees above everything else—they get paid time off to volunteer, offers plenty of activities within the community, and is very big on charitable contributions (and giving makes people happy!).

12. Starbucks

    Sure, people who work behind the counter might have to deal with grumpy people who need their double-shot espressos, but with an overall happiness score of about 4.2, they’re doing pretty well. Competitive pay, insurance packages, and quality benefits make Starbucks a great place to work.

13. Apple

    The average salary at Apple is around $42,000, but that’s because they hire all sorts of people—from recent grads to Steve Jobs-esque geniuses. People who work at Apple gave it an even 4/5 star happiness rating.

14. Quicken Loans

    You might think this mortgage solutions provider is pretty corporate and stiff, but one employee noted “Besides for the obvious perks, like unlimited free slushies and snacks, it’s a fun place to work. They encourage you to take a step back when you’re getting stressed and play one of the games they have scattered about to de-stress. We have bean bag tic tac toe and a basketball hoop in my section.” Sign us up!

15. Leidos

    A defense, aviation, information technology, and biomedical research company, workers gave Leidos an average happiness rating of 4.1—transparency, growth opportunities, and community impact are just some of the factors to contribute to that score.

16. Qualcomm

    High ratings across the board for this communications company, a 4.1/5 for average happiness, a $92k average salary, and a 96 percent CEO approval—dang!

17. iGATE

    This company offers information technology, consulting, and business process outsourcings services—and apparently lots of happy employees as well. The vast learning opportunities are cooperative management helped iGATE score big happiness scores across the board.

18. The Vanguard Group

    A provider of investment products and services, Vanguard’s goal is to help people reach their financial goals. Employees scored the company a 4/5 happiness rating with an average salary of $46,000.

19. Citrix Systems

    Citrix is based in Florida and known for providing desktop virtualization and cloud computing services. Happiness seems to vary depending on which department you work in, but overall, they’re still slightly above a 4/5 rating for overall happiness. Something tells us the average salary of $126,200 doesn’t hurt!

20. Kaiser Permanente

    At number 20, this nonprofit integrated managed care consortium offers their employees a great work-life balance, a fun and rewarding culture, and much more.

    Were you surprised by any of the companies on the list? Did your company make the list? Tell us why you like or don’t like working at your job.