The story about the three girls producing a breakthrough crop yield is complete nonsense, they didn't invent anything new.
http://www.reddit.com/r/worldnews/comments/2heown/16yearold_...
This list is also good and cataloged for other years :
Many of the mentioned "breakthroughs" are not even science but engineering.
The biggest CRISPR breakthroughs were all in 2012 and 2013- while it's an exciting up and coming biotech application, it wasn't a breakthrough of 2014.
Tokyo is saying they will have robotic Olympics in 2020 and it doesn't seem that far off.
"Science journalists" continued to misrepresent science on a regular basis.
The list is pretty good, but mesons are an entire class of particle, not a particle, so although the new particle discovered is a meson it is not the meson.
And Lockheed-Martin did not claim to have invented a working fusion reactor. They claimed to have an approach that they believe will lead to a working fusion reactor in five years or so.
Those are just two that caught my eye. It's been a good year for science, and for technology, and for humanity (mod some nitwits who think that violence and faith are good ways to improve the human condition) but science journalism is still a terrible mess.