Dish washing. I bought a dish washer and that machine gives back at least half hour of my life every day. I don't know how I lived without it. (disclaimer: I cook at home)
Second that. My first dish washer came with the house I bought. Got hooked on it so badly that I had a mild panic attack when it broke down. I didn't even try to fix it (which would have taken time) but bought a new one and had it delivered the next day.
I bought a dish washer too, but i stopped using it. Don't get me wrong, I hate the doing the dishes by hand, but this is so brainless that my mind wander and I often find myself solving problem (work related) while doing it.
