74plb

Here's my take on this. Contribute to the 401(k) if there is a company match. Free money as mentioned before.
You have a choice to make after that though. The 401(k) deductions from your pay will be pre-tax money. This will reduce your taxable income and reduce your taxes for that tax year. A Roth IRA would be funded with after tax money with no tax deductions. But(and there is always a but) the money will grow tax deferred until you retire. At that point, you can take distributions on your Roth IRA with no taxes due on the contributions or the tax-deferred growth of your money.
The Roth money can be used at anytime without tax penalties. This could be attractive if you become unemployed in the future. A emergency fund of sorts.
If you were tap your 401 before retirement at 59.5 you would pay a 10% early distribution penalty and your current tax rate on the earnings.

There is a program thatl lets you tap your Traditional IRA without early withdrawal penalties but it is not for most people.
This program is called a 72(t). It allows you to withdraw your IRA based on your life expectancy.
I have a 401 account with my previous employer, a traditional IRA and a Roth IRA.