IRA, Roth IRA, 401(k), etc. are not investments in and of themselves, but tax treatments.
Investments are things like mutual funds, index funds, bonds, etc.
When I moved employers a year ago I rolled over my 401(k) (with 100% vesting...FTW) to a traditional IRA. I went with
LKCM Aquinas Funds as they are screened according to the US Conference of Catholic Bishop's Socially Responsible Investing Guidelines. I have since opened a Roth IRA there to resume my savings.
Roth is the best, especially if you are in the 15 or 25% tax bracket...better to pay 15% now than who-knows-what in 40 years when it's time to withdraw it. It's possible the government could change the rules and find a way to tax Roth savings, but there'd be riots in the streets.