The whole idea about using cheap USB phone chargers is flawed, but without trying to sound repetitive, phone chargers are designed in a way that meet the requirements for their normal use, you normally use them to charge your phone, and it is not expected that your phone will be connected to any other electronic device with a separate power supply.
While some issues could be attributed to some particular models of TVs, my impression is that the main issue causing this type of problems is poor or not at all insulation on the phone charger power supply with floating ground (as you may have noticed not too may of these USB chargers have a ground connection.)
There is a good video (somebody posted it on the Rpi forum) showing how crappy some of those power supplies, in that particular case was for a USB powered hub (which also invalidates the argument that using a powered hub is the cure to other maladies with the Pi.)
