This was taken from http://stackoverflow.com/questions/12950538/ms-sql-2008-get-all-table-names-and-their-row-counts-in-a-db
SELECT sc.name +'.'+ ta.name TableName ,SUM(pa.rows) RowCnt FROM sys.tables ta INNER JOIN sys.partitions pa ON pa.OBJECT_ID = ta.OBJECT_ID INNER JOIN sys.schemas sc ON ta.schema_id = sc.schema_id WHERE ta.is_ms_shipped = 0 AND pa.index_id IN (1,0) GROUP BY sc.name,ta.name ORDER BY SUM(pa.rows) DESC