SQL Server: Version, Service Pack, Edition

Just run following command within Management Studio:
SELECT
@@VERSION,
SERVERPROPERTY('productversion'),
SERVERPROPERTY ('productlevel'),
SERVERPROPERTY ('edition')

As result you receive something like:

Microsoft SQL Server 2005 - ... Windows NT 5.2 (Build 3790: SP 2)
  9.00.4035.00
  SP3
  Standard Edition (64-bit)