The standard mouse has worked for a lot of people for a long time. But that certainly isn't stopping companies from trying to improve upon it. The latest new mouse design is the Jelfin Gel-Covered Mouse, which is basically the product of a normal mouse mating with a stress ball. OK!
The whole mouse is covered with gel material, making it soft and squeezable. That way, when you get an email from your boss that infuriates you, you can simply squeeze your mouse rather than punching your desk. Which is healthier, really.