I have always enjoyed Angriff (WW II miniatures rules by D. Myters and R. Zimmermann), but the biggest gripe was that the Panther and T-34 are so darn easy to kill. The reason is that the sloped armor is not taken into account in these rules. Sloped armor gives the effect of having more armor in that the round will tend to bounce or glance off rather than penetrate as it might against armor at a 90 degree angle. Anyway, without getting too much into it, here is an effective sloped armor chart.