Like a Roomba for your pool, this robotic cleaner not only vacuums up dirt and leaves, but scrubs the tiles along the water line. I have a keyhole shaped pool and it manages to find all of the areas it needs to get to and does a great job cleaning.

Watching the Tigershark move around your pool is mesmerizing. It is particularly fun if you have a layer of dust on the bottom of the pool (after heavy winds for example), so you can see the crazy path it takes.