SqlServer 08: Query to list all databases in an instance?

sqlcmd -E -S SERVER\INSTANCE -Q "sp_databases"

Notes:

• -E: Use a trusted connection ("Windows authentication"). Replace by -U username -P password for SQL Server authentication.
• -S SERVER\INSTANCE: The instance of SQL Server to which to connect. If you don't know the name of your instance, you can use sqlcmd -L to get a list.
• -Q: The query to execute. The uppercase Q causes sqlcmd to exit after executing the query.

EXEC sp_databases

or

SELECT NAME FROM sys.sysdatabases

or

EXEC sp_msForEachDB 'PRINT ''?''';

You can use sp_databases stored procedure.