Since convergence is the main issue with getting everything running on the same stuff - I'm going to assume that this isn't going to take place until well into the future. (It's actually far better to use more diverse sources of energy to prevent general scarcity issues, but that's another conversation.)

Therefore going into the future we look at sci-fi since engineers need to get their ideas from somewhere. Thus by canon we have:

• Star Trek : sustained Anti-Matter reaction (It doesn't RUN on the dilithium crystals, they're more like a part that wears out a lot)
• Stargate SG-1: Zero-Point Module/artificially created singularity i.e. a black hole in a can/crystal/whatever
• Final Fantasy : Biological Batteries - glowing jelly - don't forget to feed your laptop a spoonfull of sugar before bed
• Battlestar Galactica : They're usually pretty vague about this stuff AFAIK - but there's references to nuclear technology in there.
• Star Wars : The Force - duh
• The Matrix : Thermal People Farms and "a limited form of fusion"
• Soylent Green : also People, oops - spoiler..
• MIB : "The Galaxy"
• Foundation : Human Thought

Interesting that none of them picked up on the work of Nikola Tesla who suggested that the Earth's magnetic field could be tapped to supply almost limitless amounts of electricity. True or not, it would have made for interesting stories.

• Star Blazers - 'Wave Motion' engine
• Dune - The Spice Melange