The 'Trust Ami Mouse Scroll Pro' has to be the best mouse I have ever used. The ball tracking is excellent and it works on just about any surface. The two top buttons work perfectly, and the third side button (for use with the thumb) is well placed and can be asigned to do many different things such as Zooming, it can also be used like a normal third button. The horizontal and vertical scroll wheels can be used to scroll across and up + down. Some scroll wheels on other mice dont work very well, but I think that these are the best.