The Great Underline Debate

Are you a fan of underlines, or are you against? Do you believe they add clarity or are they an affront to the eyes?
We'll never tell you, but here are some underlines for you to peruse:
Underlines for Clarity,
Underlines as Art,
Underline Issues

Underline Issues

Here are some of the underlines that plague our world:

The overuse of underlines in everyday text
The underlining of important information without context
The underlining of things that shouldn't be underlined

And here are some subpages that address these issues:

Overline Oversight

Important but Not Underline

Should I Underline That?