Just out of curiosity, what is the primary key for this table?
Assuming by using the words "..the most recent version.." you mean the row with the maximum value of the version column for a given ContentID, then a correlated subquery will select those rows:
SELECT ContentID, Content
FROM PageContent P1
WHERE Version = (SELECT MAX(Version) FROM PageContent P2 WHERE P1.ContentID = P2.ContentID)