How do I filter a voice recording to sound like a NES game sample?
You wont get that effect with just an EQ.
try using a bitcrusher effect to reduce the bit-depth to 8 or 16 bits, maybe some saturation and a lowpass at the end to tame some of the distortion.

The characteristics of these old game sounds come almost entirely from the crazy low resolution and data compression necessary at the time to get the samples onto the game cartridge.

good luck!