1. A self-cleaning house
2. A molecular transporter, so we could hop to wherever we wanted without needing to sit in traffic or bother with aeroplanes.
3. A time machine, so I could set out late in my molecular transporter and still arrive on time.
4. An atomic rearranging machine - so you could put all your garbage in, press a button and get a steak dinner out.
In short, I'd get rid of all the boring stuff we have to do :)
Last but not least, 5. A Google algorithm neutralizer. If a Google algorithm was patently unfair, users could run this software which would disempower the unfair elements and restore the previous situation.