A diode is the simplest AM demodulator as it strips off the negative part of the signal and a simple filter removes the carrier.
However better performance can be achieved using a synchronous demodulator. Amplify the original signal so you end up with a square wave at the carrier frequency. If you have drop outs because of high levels of modulation then you can use a phase locked loop to maintain the carrier signal in the short term.
You then take this square wave signal derived from the carrier and 'sample' the original signal with it and filter. A mixer can achieve this as it is effectively multiplying the carrier (0 or 1) by the incoming signal.
At low intermediate frequencies <1MHz, a CD4016 analog switch is very effective in sampling if you bias the input to mid rail.