Immediate annuities are a vanilla product offered by almost every life insurance company. There's a competitive market for them and they don't have particularly high embedded fees. That said, they are priced based on a very conservative model--in part because their regulators require them to invest that way--and so you may well be disappointed with what you can get for your money.

The only wrinkle is the is inflation rider which can vary in the details from company to company, so is not as easy to compare, and therefore tends to be less of an efficient market (i.e. has fairly high costs for the protection you get).

One interesting thing you can do with annuities is buy a deferred annuity, again a fairly vanilla, competitive product. If you set the deferred date to well into your old age (usually 85) and no death benefit you can get a relatively large monthly payout. This then acts as a sort of insurance policy (along with social security) that insures you won't outlive your money and allows you to be more aggressive in spending the rest of it.

You should be able to get an inflation-adjusted annuity at the TIPS rate plus a credit spread. But right now that TIPS rate is effectively nothing. And I don't know whether the credit spread plus the insurance company tax benefit is a good deal.

Packaging e.g. an S&P index fund in an insurance product, so you don't pay taxes until you get payouts, would be a really good idea, but typically insurance companies tack on sales commissions and fees far in excess of e.g. SPY or VFINX. If Fidelity or Vanguard offered that, it would be a good deal, but I hadn't seen that... looking at that Fidelity product now https://www.fidelity.com/annuities/FPRA-variable-annuity/ove...