My favorite use for the middle mouse button: double-click. In other words, instead of having to manually double-click a desktop icon to launch a program or open a document, I just middle-click it.

On Windows, you can use the middle-click button to close app windows directly from the taskbar. All you have to do is hover your mouse over the taskbar icon and middle-click the thumbnail preview ...

Over in Vivaldi, you can get to the mouse gestures feature by clicking the Settings button (the cog icon down in the lower left corner), then navigating to the Mouse tab. Enable Allow Gestures to ...