I don't want to be stuck in this rotting carcass that appears living though.. cybernetics could completely solve 99.99% of all health issues. And even if we stopped aging, people would still die left and right of absurd illnesses.
Best of all, replace the entire body, and energy production could be done via fuel cells instead of food. Meaning drink a bit of water, sit a bit in the sun and your power levels regenerate... lacking either, energy bars ;p