File dialog formats list – should ‘all files (*.*)’ be listed first or last?

When creating the list of format filters for a open/save file picker dialog, should the option to show all files (e.g. 'All files (.)') be listed before or after specific format choices (such as 'Text files (*.txt)')?

My gut feeling was that this should always be listed last - but a quick survey of a few different applications revealed that it's often not, so now I'm wondering which placement results in better UX.