Best portable power source

Hello,

I´m doing some research on the best portable energy source.
All these technologies listed below have been suggested. From the past thread regarding betavoltaic energy I gather that this is some years away.
How would you rate these listed technologies in terms of effectiveness and viability?

* EEStor's Electrical Energy Storage Units


* Balanced capacitators


* Betavoltaic energy


* Advanced Solar Batteries


* Micro fuel cells


* Nuclear power through RTG-style cells


* Thermodynamicaly stable systems


* Better insulators


* Lithium Ferrous Phosphate

Thanks a lot

Peter