You just smash'm up to get the PCBs out of them, ship'm across the world to a 3rd world country, where you pay children to douse them in chemicals and light them on fire, then dig through the toxic much to fish out the metal nuggets to send out for processing.
There's a local recycling company near me, and anything like that (including monitors) has a $25 surcharge to take it, but they take everything else free of charge. It was great when I did hardware support, because we could just huck most customers' old gear at them and it got properly handled.