Chad Callihan has a mission, should you choose to accept it:
I recently ran into an error for a query that was casting XML to VARCHAR to search for a value. I have a bit of familiarity with the XML for these types of queries, so I was surprised when running the SELECT statement caused this error, which I had never seen before:
Msg 6355 “Conversion of one or more characters from XML to target collation impossible”
Click through for the solution. The real solution? NVARCHAR Everywhere.