I hate vacuuming. So, a couple years ago, I bought a Roomba vacuum cleaner from Costco as a Christmas present to myself. This robot vacuum has been a huge upgrade for our home.
I like to cook. So, one small home improvement that has improved my life a lot has been venting the over-the-range microwave fan through the exterior wall. The tools and parts were cheap, the project was fairly simple, and and it has really cut down on the smoke and odor in the kitchen and in the whole house.