Just around my house there are a lot of different sensors, but most of them are the typical on/off or trim pots. Light switchers are a simple switch, but the dimmers are like the ones potentiometers we used in class except linear rather than rotational. My roommate's antique stereo is complete with giant volume knobs that are even more similar to the rotational potentiometers. I guess that same stereo has a magnetic sensor that allows it to read the magnetic tape from old cassettes. Come to think along those same lines, the DVD player has a light sensor that it uses to pick up the laser light that bounces off the DVD itself. The camera that connects to the PS3 is a type of light sensor as well, albeit a more sophisticated one.
Moving on to the kitchen there are pushbutton switches on the microwave and the dishwasher and a nice little temperature sensor inside the oven. I would imagine the fridge has a temperature sensor as well, not to mention that tricky little switch that always manages to keep us entertained by flipping the light on and off when we open and close the door. The reptile tank in the corner has a different kind of temperature sensor that uses infrared light rather than heat thats conducted directly onto it. The capacitive touch sensor on my phone is pretty swell.
Hmm, I think that might be all the interesting ones.