A slight alteration to the BRILLIANT work by kempfjb with his/her AddSimilar extension, but with some post-sorting action within VLC and in the table processing.
Do you have sorted folders for your media files? Do you want to have those files play in sequential order automatically? Simply play the first file of your choosing and select this extension - it will find similar files within that folder and automatically add them to the VLC playlist, then sort them by title. So, if you have VideoS01E01.avi through VideoS01E15.avi, it will just keep playing through the files in episode order.
To install, download this lua file and place within your VideoLan application folder under VLC,lua,extensions folder. Then run a video file and select Add Similar With Sort from the View menu.
Here is the link to kempfjb original Add Similar extension: http://addons.videolan.org/content/show.php/Add+similar+files+from+folder?content=140699