A bit mundane, but the moment that stands out for me is on a map that I don't see in rotation anymore. I can't recall the name, but it was the bridge spanning the frozen river, with the Soviets on one side and the Germans on the other (with a small village on the river to the western side of the map).
Anyway, I was playing a Soviet and I was at the entrance of the bridge on the Soviet side when the German commander drops the most intense artillery barrage I've experienced in-game. One round impacting after another, on and on for what seemed like 30 seconds straight and I was stuck, in the prone, without cover, smack in the middle of it. My speakers are roaring these literally deafening booms from the artillery shells exploding and I can't really see anything because my screen is basically blurred black and red, so I just picked a direction and started crawling. Eventually, I crawled beyond the danger radius of the artillery strike and the bombardment ceased.
But seriously... that was the only moment in any game ever where I was genuinely, like, "Holy CRAP!" and wincing at the repeated explosions.