My most memorable moment in this game was probably when my friend and I went ahead and decided to learn how to drive a tank in the midst of battle.
When we spawned in, our tank crew went as follows: My friend as the driver, me as the person manning the tank's actual gun, and a random person operating the machine gun. Our crash-course, self-led tutorial basically consisted of my friend driving in circles because he could hardly see anything out of the driver's slit; me not being able to shoot the gun properly because the tank was constantly moving, resulting in tank shells being fired haphazardly around; and the machine gunner, who knew what he was doing, yelling at us and calling us incompetent idiots. I proceeded to accidentally pop my head out through the tank's top, only to instantaneously be shot. My dead body slumped back into the tank cockpit and awkardly jostled there as everything in the tank was suddenly painted with my blood. I can imagine Russian soldiers peeping out of their foxholes, only to comically spectate a German tank spin around, firing randomly and carelessly.
Later in the siege, our commander called in artillery on friendly positions and we lost.
I think they actually kill employees to record the game's death screams. Red Orchestra 2 can easily be named 'PTSD Simulator 1942.'
Seriously, though. This game is great. Easily one of the best World War II shooters I've ever played. Shots kill you instantly (If you're lucky enough to survive a bullet, you usually just sit in sadness as you listen to your character scream or cry to death as they bleed out), the carnage feels authentic and the atmosphere is truly war-like. The developers really harped on realism, and I can say they nicely achieved it.
That's not to mention the soundtrack is proud and patriotic, while at the same time solemn and depressing.
The only problems I can think of is the game are its graphics-intensive nature, so you need a decent computer to run it, and the game is so structured around teamwork that an incompetent team can really rain on your gameplay experience (Or boost it, depending on the scenario).