It doesn’t happen too often that you discover something worthwhile on YouTube about high energy physics after you read a lot about the basic things in this area. This video here is an exception:
I liked it a lot.
Two other sources on YouTube come to my mind when it comes to physics: PBS Space Time – for a channel with a focus on astrophysics it covers surprisingly much fundamental physics;
the other is Fermilab’s channel with the always (trying adorably hard to be) funny Dr. Don Lincoln.
Sometimes, minutephysics has nice stuff, too, like his series on special relativity.
Another gold nugget I found is the infinityplusone blog. It’s a lot of interesting maths, not dumbed down too much, e.g. the series on Gödels incompleteness theorems, plus it has awesome and cute drawings.