I guess I can't think of a specific battle off hand, but I'd check into Operation Cobra. I believe that involved the allied breakout after Normandy. Thats when the more open terrain allowed the newly arrived, large amounts of allied armor to maneuver, therefore creating large tank to tank engagements. While the eastern front is known for massive numbers, I think this setting of WW2 is often overlooked when thinking of armor battles.
HeadBang