Should primary keys be always assigned as clustered index

Question

I have a SQLServer table that stores employee details, the column ID is of GUID type while the column EmployeeNumber of INT type. Most of the time I will be dealing with Emp

Answer 1

Since EmployeeNumber is unique, I would make it the PK. In SQL Server, a PK is often a clustered index.

Joins on GUIDs is just horrible. @JNK answers this well.