Most electronics like TVs, DVD players, etc do not work at 230 V. These appliances have an internal device called SMPS (Switch Mode Power Supply) which converts incoming 230 V to 12V or 24V (whichever is required by the appliance). Thus none of the electronic appliances need voltage stabilisers.
I repeat, electronic appliances do not need voltage stabilisers. They are neither impacted by high voltage, nor by low voltage. So electronic devices do not need any protection. There are products available in market because people feel the need of protecting their appliances, but these devices do not need any protection. The power consumption of electronic products does not change with voltage fluctuations. Also, their output does not change.