What's the simplest way to personally archive web documents?

I'm a bit of pack rat for web documents, because I can't stop to read everything I want to. I'd prefer to keep a copy for myself in the event the source material disappears. It's not uncommon for me to browse my collection and read something from 6-12 months ago.

I don't usually like bookmarking services because my current collection of archived documents spans a longer period of time than they've usually been in business.

An ideal solution to me would be a PDF or compact reader-mode style document saved locally, or emailed to me. I've hacked together various solutions to this, but I've never quite been satisfied.