It depends on the amounts, but the taxes are probably higher on the lump sum. You can try using the TaxCaster. Put in your other income, and then either 12 months of the annuity or the whole amount.
TaxCaster tax calculator
However, what happens to the annuity if you die, does the remaining amount go back to the annuity company or can it be inherited? If this is an annuity that ends and can't be inherited, then the most important question is not about taxes but about your health, do you think you will live long enough to beat the annuity and get more in payments than the lump sum. You might also want to think about the rate of return on the annuity and whether you can do better picking your own investments.
Taxes shouldn't really be the top factor in your decision.
