A rice cooker. I was sceptical for a long time, because we can just cook rice in a normal pot? But the result tastes a lot nicer and feels surprisingly more convenient, and keeping rice warm for longer periods is also handy. As a result we eat a lot more rice (and are less tempted to just order in when we're feeling lazy).

Also, a Hario V60 + Fellow Stagg EKG Kettle, really upped my coffee game. Though if you include the Timemore C2 grinder it probably comes to just over $200.