The solution to a great grease gun is CLEAR

Here's a great tool for the toolbox.

These have become very popular in many industries. I have the pistol grip version in my toolbox.

They are available in multiple colors as well to differentiate between applications.

For instance you might use BLUE for food-grade applications, RED for multi-purpose and GREEN for electric motors.

The lock on coupler is great as well. Especially if you are using a whip hose and a lever style gun.

There is also a battery powered version.