How about:

WITH cteUsersAndSoftware(UserName, Software)

AS

(

SELECT DISTINCT s.User_Domain0 + '\' + s.User_Name0 AS 'UserName',

(CASE

WHEN p.DisplayName0 LIKE 'Microsoft Visual Studio% %Ultimate% %2013%' OR ... THEN 'Microsoft Visual Studio Ultimate 2013'

WHEN p.DisplayName0 LIKE 'Microsoft Visual Studio% %Ultimate% %2012%' OR ... THEN 'Microsoft Visual Studio Ultimate 2012'

.

.

WHEN p.DisplayName0 LIKE 'Microsoft Visual Studio% %Professional% %2005%' OR ... THEN 'Microsoft Visual Studio Professional 2005'

END) AS 'Software'

FROM dbo.v_Add_Remove_Programs p

INNER JOIN dbo.v_R_System s ON p.ResourceID = s.ResourceID

) , cteRank as (

SELECT cte.UserName

, rank() over (partition by cte.UserName order by rnk.vsVersion) as ProductRank

, rnk.vsVersion

FROM cteUsersAndSoftware cte

INNER JOIN #swRank

rnk ON cte1.Software = rnk.vsVersion

)

select * from cte

where ProductRank = 1