Here's a simple, quick and reliable query that will give all database and log file names, sizes and also database statuses (e.g. ONLINE) in a nice, easy to read output:
SELECT
D.name,
F.Name AS FileType,
F.physical_name AS PhysicalFile,
F.state_desc AS OnlineStatus,
CAST(F.size AS bigint) * 8*1024 AS SizeInBytes,
CAST((F.size*8.0)/1024/1024 AS decimal(18,3)) AS SizeInGB
FROM
sys.master_files F
INNER JOIN sys.databases D ON D.database_id = F.database_id
ORDER BY SizeInBytes desc