I _always_ favoured /markup/ done like *this*.
[download]

becoming

I always favoured markup done like this.

Paragraphs are simply blocks of text with no intervening blanks lines.
Paragraphs are simply blocks of text with no intervening blanks lines.
Paragraphs are simply blocks of text with no intervening blanks lines.
Paragraphs are simply blocks of text with no intervening blanks lines.

This is the start of a new para.
[download]

Paragraphs are simply blocks of text with no intervening blanks lines.Paragraphs are simply blocks of text with no intervening blanks lines.Paragraphs are simply blocks of text with no intervening blanks lines.Paragraphs are simply blocks of text with no intervening blanks lines.

This is the start of a new para.

1 This is an H1 header

Header lines are single lines starting with a numeric with blank lines
+ above and below.

-list item 1
-list item 2
--nested list item 1
--nested list item 2

This is a para subordinate to the second item in the nested list.
  
and another.

--nested list item 3
  The nested list ends with the -- line below.
--
-list item 3
-
=================
Any line consisting of say half a dozen or more =s becomes an HR.

This is the final paragraph in this example.
[download]

This is an H1 header

Header lines are single lines starting with a numeric with blank lines above and below.

• list item 1
• list item 2
  • nested list item 1
  • nested list item 2

    This is a para subordinate to the second item in the nested list.

    And another.

  • nested list item 3

    The nested list ends with the -- line below.

• list item 3

Any line consisting of say half a dozen or more =s becomes an HR.

This is the final paragraph in this example.

This seems easy and intuative to type, relatively easy for the human eye to parse and see the intent in its raw form and uses simple enough rules to make it faiirly simple to perform the conversion process.