Email newsletters are great, sure you can go to websites such as Sitepoint or Smashing Magazine and view articles themselves. But I find receiving newsletters makes sure I read the most relevant and important articles at the end of a week.
I mostly sign up for newsletters to keep myself up-to-date with the latest web design news, and tend to get these emailed on Friday; this gives me some reading material for the weekend.
These are some of the newsletters I highly recommend:
If you have your own favourites, please mention them in the comments.