So far the best place is dark woods, there are only 5 there. Everywhere else seems to have 8-9. Coldplains is a BAD idea, clones take on the boss traits and they will be fire enchanted and explode and kill you!!! Remember, The clone spawns and the group turn into clones. Choose wisely!
The power of Diablo ll gets stronger as time goes on! It keeps pulling you back!