If you're thinking of changing careers, Yahoo.com has a list of the four most satisfying jobs in the United States. These jobs are based on opportunity, salary, flexibility, and how easy it is to advance your career. Here's the rundown.

Here’s the list according to Yahoo:

1) Freelance Graphic Designer. It's creative, and you can work from home. According to the American Institute of Graphic Arts, the average freelance graphic designer makes around $55,000 a year. Not too bad right?

2) Hospital Administrator. The Department of Labor predicts steady growth in the healthcare industry through at least 2018. Health care managers make $90,000 a year on average.

3) Critical Care Nurse. According to a survey done by the University of Chicago, jobs that involve helping other people rate highest in job satisfaction and according to the Department of Labor, the average critical care nurse made around $66,000 in 2009.

4) Quality Assurance Managers for Software Companies. According to a 2010 poll, 45% of them have flexible work schedules. And after five years, the average salary is around $85,000.