“Your local electronics store has just started selling time machines, anywhere doors, and invisibility helmets. You can only afford one. Which of these do you buy, and why?” –The Daily Post
I think an invisibility helmet would be the most fun but a time machine would be the most practical. With the ability to travel through time, you could make your life completely perfect. Every time something goes even slightly wrong, just jump back in time a few minutes and try again! Plus, you could go into the future and always know what is about to happen and prepare yourself for it.