Advantages to a 401k Plan

The employee decides how much money to enter into the plan, which makes the employee responsible for his or her own future.
Any earnings in your 401(k) account grow tax deferred. Since earnings are not taxed until they are withdrawn there are more real dollars working in your investments.
A typical 401(k) plan provides the employee with a number of different investment options, allowing them to be as conservative or as radical with their savings as they want.
Employees have the ability to "roll over" their savings if they decide to leave their current employer for a new job, so none of their savings is lost.
Employers may provide "matching funds," meaning the employer puts in a percentage of what you have already added to your 401(k) plan.
Automatic payroll deductions make saving for retirement easy. You are less likely to miss money you never see.