Dashes: em, en...and tildes

In my occasional series on punctuation, I have reached the dash. Dashes used to be very popular back in the days when a book might begin, "I took a handsome to --- Street, in the small market town of ---, with a view to calling on Lord ---", a sentence that makes me want to hit the author with a rolled-up newspaper until he stops being so annoying. And in more devout times, when the third commandment was taken seriously, characters were wont to exclaim, "By G-d, sir!", another handy use for the dash.
These days many writers have an irrational dislike of brackets, and tend to use dashes instead (I like both of them). But what kind of dash do you use? If you are traditionally published, you won't get a choice; the publisher's house style will decide. As an indie, you make up your own mind.
It's the mark of an amateur to use a hyphen where a dash is intended. A hyphen with no spaces either side is even worse, and plain confusing. In typography you have the choice of an em-dash, so called as it is the width of a capital M with no spaces, or an en-dash, the width of a capital N with a space either side. I prefer the en-dash (as used by Penguin) because the spaces allow the text to flow better in digital format, where em-dashes can result in ugly gaps in the text.
And the tilde? For this post I looked it up on Wikipedia, and rather wished I hadn't. I almost certainly don't need to know all that, and neither do you. But it's one of the prettier punctuation marks.