If you've got a ton of money to put away for retirement, you can generally use both a ROTH IRA (if you qualify) and a 401(k) or other employer-provided retirement plan. The 401(k) might disqualify you from contributing to a traditional IRA, but most of that does not apply to a ROTH IRA.
The ROTH IRA is actually pretty darned cool. You contribute post-tax income, yes, so you don't get the near-term tax breaks that you do on a tax-deferred option like a traditional IRA or 401(k). However, since you've already paid taxes on that money, you pay NO TAXES when you take distributions post retirement even on your gains! You ALSO can take funds back out under most circumstances (there are a few restrictions) with no penalties even prior to the retirement age as long as you limit your withdrawals to only what you contributed (no gains). This means you can use it as a sort of emergency fund/long-term savings vehicle, in addition to just a retirement plan.
Now, since you'll probably have low income during retirement, you will probably also want some tax-deferred savings available to you, especially if you make a fair bit of money right now, in order to take advantage of the lower marginal tax bracket you'll be in during retirement. If your job offers a 401(k) or SEP, SIMPLE IRA, etc., that's your tax-deferred option, and you can either split your contributions between them and your ROTH IRA or, possibly, depending on your circumstances (talk to a tax advisor), max both of them out. If your company does not offer a retirement plan, you should be able to split your maximum IRA contribution (~$6500/yr) between a traditional and a ROTH IRA.
You can have the money in your ROTH IRA managed just like a traditional IRA. That is, you can either have an advisor manage it for you, or you can basically just have some "advisor" be the mandatory custodian and manage it yourself (E*Trade, etc.). Honestly, you probably won't do much better than just taking the latter option and dumping it all into some low-cost index funds unless you've got a fair bit socked away in the account. and even then, it's questionable. Simply having one that you otherwise mostly manage can be fairly low cost. Something on the order of $20/yr for account "maintenance".
I use a ROTH IRA as my primary retirement savings means at the moment.
If you have a high-deductible health plan, you should also look into whether you qualify for an HSA that you're not taking advantage of. You put tax-free/deferred money into them, and most any health related expense can come back out at any time totally tax-free. Once you hit 55.5, you can start withdrawing from it tax-deferred just like a traditional IRA. So, it's more flexible than a traditional IRA with similar planning type benefits. It also has a separate contribution limit from your IRA(s), so you can sock away even more money if you're able to.