Glen Berry posted a collection of queries that can be used in diagnosing SQL Server 2005/2008 metrics/counters.
"… small collection of queries that can be used to gather a wealth of very useful information about a SQL Server 2005/2008 instance, and about any specific database on that instance. These queries will tell you the exact version and edition of SQL Server, whether it is 32-bit or 64-bit, the OS version, and some information about the CPUs and memory in the server. They will also reveal how many databases are present, their recovery models and file layouts. We also find out what the top wait stats are, along with Page Life Expectancy (PLE) …"
You can find the full post and script here: