I forgot the biggest and easiest way to get rich which is a ROTH IRA. You can only put a limited amount of money into it every year, but over 20-40 years you will be a millionaire or multi millionaire. Go look at a calculator online or talk to your bank to see what options they have but that is the #1 best way to be rich in your life.
How would a retirement plan make you rich? Multimillionaire? Huh! Funny.
Quoted from Wikipedia.org:
A Roth IRA (Individual Retirement Arrangement) is a retirement plan under US law that is generally not taxed, provided certain conditions are met. The tax law of the United States allows a tax reduction on a limited amount of saving for retirement. The Roth IRA's principal difference from most other tax advantaged retirement plans is that, rather than granting a tax break for money placed into the plan, the tax break is granted on the money withdrawn from the plan during retirement.
Roth IRA is only available in the US and you have to meet certain conditions. It just reduces your tax for your retirement. It's not some kind of investment that would make you rich after 20-40 years. I don't know how much exactly would you get from this but I'm pretty sure it might be big for someone who's retired but it wouldn't make you rich.