Domino

Looks like your Sennheiser CX 300s have got good reviews, I bet they will sound great

These are the current in ear headphones i use. The sound in general is crisp and balanced with full, deep and balanced bass. I am really picky when it comes to sound, but these I can wholeheartedly recommend. http://www.bowers-wilkins.eu/Headphones/Headphones/C5/overview.html EDIT: Oops, just noticed you wrote up to £20.

Smells like a bad HDMI cable. Have your tried different and/or a shorter cable? I know you can get jitter with too long cables, and big temperature changes. If this just started happening then I would take a look at any new equipment installed in the vicinity of the screen, or the equipment you cable run goes through. If you're using a reciever, or computer as your image source then try removing or changing equipment to see if the problem persists. If you still have the exact same problem after changing cables, shortening your cable run, and changing the image source, then the likelyhood of something being wrong with your TV increases a lot and you will probably have to fix it. Good luck!