my favorite would be my center channel speaker....amazing bass from a center!
least favorite would be my dvr (like many posters above). it's constantly unresponsive or requiring me to get off my lazy butt and open the flap to push the red reset button to restart it. then it gets to download all the info again for like 10 minutes while I miss the end of whatever show i was watching...happened to me once during a ufc ppv main event bout with Randy couture while I had a house full of people....GRRRRRRRRRR!