I have just seen a user tag several questions with controller, previously nonexistent. I find this an unfortunate coinage, since the term ‘controller’ is ambiguous: it may refer to game controllers (gamepads, joysticks, paddles), or it may refer to bus controllers (chips and extension cards that handle communication with other devices, e.g. the 8042, SCSI cards, USB host cards, ATA/IDE cards). Both of those are pretty topical for this site. (The ambiguity sticks out like a sore thumb in the case of Mind-Controller User Input from the late 90s, where usb is followed by controller in the tags list, but the question isn’t about USB controllers.)
I think input-devices is just as adequate for the questions I saw tagged, and thus preferable as more clear.