I wonder if there is a way to have a ruler displayed between the 80th and the 81th character in vim. I know that one can highlight the 81th column, but that actually looks as ugly as something from the DOS era. Is there a way to display a pretty ruler like the one in sublime?
Unfortunately not possible in vim; painting color on anything less than a full cell is not possible for (most?) terminals. There are several other options available, such as changing changing background color for text when it overflows the 80 character limit, though.
This thread, while being about a different issue, provides several alternatives to a normal color column.
As @Wolfie said, there is no way to make the 81st column look pretty. Personally I color column 81 and up. This looks decent and does not distract me too much. Try it with the following statement:
:let &colorcolumn=join(range(81,999), ',')