Like Charles said, we won't be able to name the "best" account without more information. You are looking for the best account for your retirement goals, but we don't even know what these goals are.
Usually, if you work for an employer who offers a 401k, it can be a good start, especially if there is a matching contribution. This 401k can offer a number of investment funds that you can choose from.
If you don't have a 401k through your employer, or if you are self employed, own your business, etc., you can look into setting up an IRA account. This will come with an even wider range of investment choices
Then there is Roth account (Roth IRA, Roth 401k, etc.) which allows you to contribute after-tax money and receive tax-free earnings.
I would suggest searching this site for similar questions or talking to a financial advisor to discuss your goals and financial situations.