It's best to have the most current Service pack; Service Pack 2 is the most recent service pack for SQL Server 2008 R2.
See this article for more details.
"I cant stress enough the importance of switching from a sequential files mindset to set-based thinking. After you make the switch, you can spend your time tuning and optimizing your queries instead of maintaining lengthy, poor-performing code."-- Itzik Ben-Gan 2001