Get The DBO From All SQL Databases

I have finally decided to start keeping track of the useful SQL commands that I have used.  Mostly because I am tired of rewriting them.  Also, if I have had to use them, then I sure that someone else (or me again) might find them useful.
While moving databases around within SQL to optimize IOPS and/or drive utilization, you might have a need to put the Database Owner back to what it was originally. Before you drop your databases, take a look at the DBO first.
This will grab all the dbo's of all the databases on your server:

select SUSER_SNAME(owner_sid) as username, name from sys.databases

Now, if you want to change the DBO...

sp_changeDbOwner @loginame = 'domain\username'

However, you might run into an error is the DBO is already a user or aliased in the database.

To fix this problem, run the following:

USE <databaseName>
GO
SP_DROPUSER 'domain\username'
GO
SP_CHANGEDBOWNER 'domain\username'

UPDATE 02/04/2015
Added drop user and change owner code.