Hi Nick,
Regarding Brian Cox, the second series "Wonders of the Universe" covers more topics. There were only 4 episodes tho. In general, Brian Cox goes into the physics of things. I like that he talks slowly so I have time to take in what he's said.

The first series was just focused on our solar system only.
+1 with Bert's suggestion- ZZZFROMHELLZZZ is one of my very favourite YouTube channels.
Unfortunately he's lost quite a few good videos recently- I notice some IMAX ones missing (copyright-lucky I grabbed mine when I did!) but he's still got a great selection there.
Here is my favourite YouTube Channel.
Cosmic Journeys: Season 1
Cosmic Journeys: Season 2
These docos by the way are "thinking" docos and by far the best docos I've seen todate. They only run for about 20mins each but they pack a ton of education into them.
For learning, I just can't go past PBS Nova documentaries. One of my favourites is "Hunting The Edge Of Space". It's a two hour doco that covers everything invented to look at the night sky, starting with Galileo to modern day.
Hunting The Edge Of Space: Part 1
Hunting The Edge of Space: Part 2
Brian Greene's brilliant & latest series on Nova... "The Fabric of the Cosmos"-
Universe or Multiverse
What is Space
The Illusion of Time
Quantum Leap
BBC documentaries are really good as well. There are more, you'll just need to search for them.
BBC Horizon To Infinity and Beyond
BBC: Faster Than The Speed Of Light
"In September 2011, an international group of scientists has made an astonishing claim -- they have detected particles that seemed to travel faster than the speed of light."
Brilliant doco, really enjoyed it.
Lastly, check out
Hubble Site Channel. This is a good teaching channel. It maybe a bit simple for you, but nevertheless I still enjoy its content.
I've just watched
Hubble's Universe from that site and enjoyed it. It explains the Hubble Deep Field and Hubble Ultra Deep Field images.
This may turn out into a really informative thread- we might get some great sources for documentaries to help us all. Thank you.

I'm a space doco junkie