I have personally switched to SQL Server 2014 few months ago and I am happy with its performance and robust behavior. Many of the customer and clients are still using SQL Server 2012. However, if you are using SQL Server 2008 R2, I suggest that you look at upgrading to the latest version of SQL Server or at least update your software with latest service pack.
You can download SQL Server 2008 R2 Service Pack from following link:
UPDATE: If you are still using SQL Server 2008, I strongly suggest that you upgrade it to the latest version of SQL Server as SQL Server 2008 is now no more officially supported by Microsoft. However, the reality is that still today, I get lots of customers who are still using this version of SQL Server.
Reference: Pinal Dave (https://blog.sqlauthority.com)