Aconcagua. there are 3 prized mex. volc. (popo, orizaba, ixta. in order of popularity) versus one Aconcagua and the climbing season is longer in mexico. if you want to avoid most of the crowds on Aconcagua, stay away from the normal route. The Polish glacier is less crowded and is equivalent to an easy/moderate volcano climb in the NW in terms of technical difficulty.