ORIGINAL: PKH
I think it's the most covered front because it's the most interesting in terms of evolution of equipment, varied terrain, weather effects, evolution of strategy, big strategic mistakes done, quality vs quantity in terms of forces, and a long struggle where both sides could have won.
Most of the fronts in World War One have you beat on evolution of equipment and strategy with equivalent variations in terrain and weather effects (granted it's pretty damn hard to beat the strategic and operational mistakes of the WW2 East Front, which hardly matters in a game because no game can ever model that effectively since you take over the job). The "quality vs quantity" aspect is one of the most perpetuated fallacies around in all of wargaming, especially after the first year on the Eastern Front, and has a far better concrete base in WW1 East Front than WW2.
