My ambush on a p4 with a t34 attempting to ram and having mud (back in the day) hinder the ramming t34 allowing the p4 to escape. That was a memorable rage moment, having terrain cancel my ambush
another classic is when you try to set up an ambush with mg or AT gun and you place it unintentionally at a sight blocker because you don't know thats a side blocker or it's just that 1 pixel too far behind the sight blocker