I use a plastic wire channel that comes with an adhesive backing, which I painted the same color as the wall to pass all my cables behind the TV. It goes up to the bottom of the TV and behind the TV cabinet.
I bought a cable management box for my power bar, so that I can put the unsightly extra length of power cables and wall warts out of sight, I try to regroup all these cables together to make one single path of cable, all tied together with velcro.
For the I/O (HDMI, etc), I plug them all, put them in the wire channel and pull the extra length so that I can coil them behind the TV and attach them to the TV rack so nothing hangs out.