401K vs. Roth
This depends on whether or not you believe you will be paying a lower tax rate in retirement. If you believe you will be taxed at a lower rate in retirement then IRA/401K is a better deal. If you believe that you will be taxed at a higher rate in retirement then the Roth is a better deal.
Some advisors, like Suzy Orman, believe that the US government will, of necessity, have to raise tax rates some decades from now. In which case you probably will be paying a higher tax rate when you retire than now, suprise, suprise. Suzy recommends not contributing to the 401K except to the minimum extent that your employer provides a match. Always claim as much free money as you can. After that, Suzy says, fund the ROTH and taxable mutual funds/stock etc.
This all depends on how the tax laws change and is hard to predict exactly. Your mileage may vary.
Sorry, I guess that doesn't answer which is better for college savings. I think the ROTH would be preferable for reasons Joe points out in his "long" answer.
[This message has been edited by blackdog (edited February 01, 2005).]