[Recycled Spooge]

I based my list on a balance between being revolutionary, the impact in history, and popularity.

1. AK-47 - Everyone knows what the AK-47 is. It is the most successful and widely used assault rifle in the world.
2. Luger - One of the most popular guns if not the most popular guns in the world. They were a huge leap from the revolver.
3. Maxim - Forever changed military strategy buy being one of the first machine guns.
4. Vickers - Same as the Maxim.
5. Mauser Kar98K - Most successful bolt-action rifle, and copied by many natoins: Springfield, Lee Enfield.
6. PPSh-41 - A highly successful submachine gun used by the Soviets in WWII.
7. Thompson - Mostly only popular in the U.S. It was used by the mafia, and it was widely used in lots of movies. It was also used in WWII, obviously.
8. M1 Garand - The best combat rifle of WWII.
8. Stg-44 - First ever assault rifle.
9. Mg-42 - One of the world's best machine guns.
10. M16 - Eh... I couldn't think of a rifle for number ten. :P