This week's list of largest Milwaukee area-based private companies is filled with 50 that run the gamut with total revenue for the latest fiscal year of $99 million all the way up to $27 billion. Not surprisingly, Milwaukee-based Northwestern Mutual is No. 1 on The List. The response for the list of largest private companies again this year was enthusiastic, with most proudly proclaiming a successful year gone by. However, you might notice a few companies you thought would make The List are not…