Federal Employee Retirement System (FERS) includes a pension based on the number of years of service.
As an intern I would use the gym as often as i could but that was all i cared about.
Internship had no benefits other than use of the on-campus NASA facilities and services, and free admission to the local science museum. On campus gym was a great benefit though.
Flexible work hours, access to FERS
Good pay for a postdoc
They have a gym everyone can use plus a nutritionist you can talk to when you want.
Contractor, 401 K is immediate, their are other plans that are nice. I chose the high deductible cheaper one. They put money into an account every week. It amount to about $1,000 a year and can just be randomly used for any medical expense. Can be used for LASIK (I know specifically). Tuition reimbursement program
Intern, so did not have a benefits package.
Government Thrift Savings Plan (TSP). Onsite fitness center and daycare.
List based on reports from current and former employees. It may not be complete.