If you want a quick way to determine which format, or style, to specify when converting a datetime value in SQL to a character data type, you can use this simple PowerShell script. Or you can look at the MSDN page.

0..200 | %{
    Invoke-Sqlcmd -ServerInstance . -Query ("SELECT num = {0}, CONVERT(varchar(100), GETDATE(), {0})" -f $_)
} | ft -AutoSize