Digging through the internal statistics and various DMV's, a few queries were found to be causing most of the problems. One query in particular was found to have 192 tables as part of the join. Given that a join with 10 tables can have over one million possible join orders, 192 tables was most likely astronomical. On his blog, Benjamin Nevarez has written about the number of possible permutations as the number of tables in the join increases. You can find it here: Optimizing Join Orders.
If you just want a quick overview,
here is a reprint of the table posted in the article by Benjamin Nevarez: