To me, the unquestionable best appliance is the washing machine and the second place in my personal ranking is the freezer-refrigerator.
If I had to choose 5 devices among them, I would make this ranking:
1 - mobile phone, I don't like to speak by phone but I make ramblings I've seen as useful it is when people is lost.
2 - digital camera I love to take photos and If I don't like a photo, I can remove it at the same moment.
3 - memory card (digital camera).
4 - mp3 player (walkman is heavier).
5 - remote control.
Unlucky I can not explain any anecdote about mobile phones at present.