For no scientific reason but what my palm is telling me, I think that the best mouse on planet right now is the Logitech G9, small and extremely customizable (even in its size).-
In contrast to its price and greatness, my G9 started to misbehave. It registers two left-clicks in press of once. No, it is not the faulty drivers. I didn’t install them. It is the Omron microswitch to blame.
So, this mouse is in need of an operative treatment.