Fusion, but proper containment of the plasma, using the remarkable technology of stable and reliable gravitational fields.  A gas energy-transport buffer-blanket that conducts the energy from the reactor core to the power transport apparatus with no leakage of ionizing radiation.  Power-beam technology that conducts the energy from the reactor to the point of use with no line loss.  And not least, a design life of 10 to 15 billion years WITHOUT refueling.  

A prototype that works.  

And they are trying to sell us a reactor that dies after seven years and leaves your backyard a superfund site!

Really!