The New York Times scrapped the off-the-shelf CMS they were using for a completely custom CMS; I don't know exactly for the LA Times, but I'll bet they're running on custom code, too.
The best technology possible is different for each use case, and unless you're the New York Times or the LA Times, it's very likely not a CMS that's been tailored for large-scale international newspapers.
All that said, if you need build a site that runs a Media property like a newspaper or magazine, consider Drupal. Check http://groups.drupal.org/node/5100 and http://buytaert.net/tag/drupal-sites to get an idea of who's running it. It's also great for NPOs and universities, as well.