When designing tables, I\'ve developed a habit of having one column that is unique and that I make the primary key. This is achieved in three ways depending on requirements
GUIDs can be used as a primary key, but you need to create the right type of GUID so that it performs well.
You need to generate COMB GUIDs. A good article about it and performance statistics is The Cost of GUIDs as Primary Keys.
Also some code on building COMB GUIDs in SQL is in Uniqueidentifier vs identity(archive).