Very simple script that list the total size of a database and its transaction log.

If you need for SQL 2000 click here

/*
DESCRIPTION    List space used on databases
 
CONFIGURATION    none

 
Compatibility list:
MSSQL2012
MSSQL2008
MSSQL2005

DOES NOT WORK
MSSQL2000

 
*/


SELECT
    SERVERPROPERTY('SERVERNAME') ServerName,
    SERVERPROPERTY('IsClustered') IsCluster,
    SERVERPROPERTY('ProductVersion') AS ProductVersion,
    case 
when RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 6.3 then 'Windows 2012R2'
when RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 6.2 then 'Windows 2012'
when RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 6.1 then 'Windows 2008R2'
when RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 6.0 then 'Windows 2008'
when RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 5.2 then 'Windows 2003'
when RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 5.1 then 'Windows XP'
when RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 5.0 then 'Windows 2000'

else RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)
end,
    DB_NAME(db.database_id) DatabaseName,
    (CAST(mfrows.RowSize AS FLOAT)*8)/1024 RowSizeMB,
    (CAST(mflog.LogSize AS FLOAT)*8)/1024 LogSizeMB
FROM sys.databases db
    LEFT JOIN (
    SELECT database_id, SUM(size) RowSize 
    FROM sys.master_files 
    WHERE type = 0 
    GROUP BY database_id, type
				) mfrows ON mfrows.database_id = db.database_id
    
    LEFT JOIN (
    SELECT database_id, SUM(size) LogSize 
    FROM sys.master_files 
    WHERE type = 1 
    GROUP BY database_id, type
				) mflog ON mflog.database_id = db.database_id
WHERE
	db.database_id > 4

  For SQL 2000

/*
DESCRIPTION    List space used on databases
 
CONFIGURATION    none

 
Compatibility list:
MSSQL2000

 
*/

SELECT
    SERVERPROPERTY('SERVERNAME') ServerName,
    SERVERPROPERTY('IsClustered') IsCluster,
    SERVERPROPERTY('ProductVersion') AS ProductVersion,
    case 
when RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 6.3 then 'Windows 2012R2'
when RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 6.2 then 'Windows 2012'
when RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 6.1 then 'Windows 2008R2'
when RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 6.0 then 'Windows 2008'
when RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 5.2 then 'Windows 2003'
when RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 5.1 then 'Windows XP'
when RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 5.0 then 'Windows 2000'

else RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)
end,
    DB_NAME(db.dbid) DatabaseName,
    (CAST(mfrows.RowSize AS FLOAT)*8)/1024 RowSizeMB,
    (CAST(mflog.LogSize AS FLOAT)*8)/1024 LogSizeMB
FROM sysdatabases db
    LEFT JOIN (
    SELECT dbid, SUM(size) RowSize 
    FROM master..sysaltfiles
    WHERE groupID = 1 
    GROUP BY dbid, groupID
				) mfrows ON mfrows.dbid = db.dbid
    
    LEFT JOIN (
    SELECT dbid, SUM(size) LogSize 
    FROM master..sysaltfiles
    WHERE groupID <> 1
    GROUP BY dbid, groupID
				) mflog ON mflog.dbid = db.dbid
WHERE
	db.dbid > 4