Marine
A Marine was part of the Navy, they simply were the Navy's infantry but wanted to be there own branch. They can fight in smaller numbers where the Army can't fit into, there the people who go in first and hold off a place untill the Army can hold it and capture it, they are a pretty cool branch and desirve the highest respect as does the Army,Navy,Coast Guard,Airforce does. =)
Marine: O dude i just passed boot-camp, im a Marine now!

Army: O dude that's great i hope you get alot out of it, i just got my airborne wings, yay!

Marine: Dude that's insane, were going to get laid

Army: Hell yeah! well anyways i have to go jump out of a plane and kill 1,000 terrorists. Cya!

Marine: O ok broski, i have to go an hour ahead on a boat with 9 other guys and hold some place before you get here, Cya soon!

Army: Save me some kills!

Marine: There will be plently

Both: Haha