Robert C. Martin
The 'Master Craftsman', I've read some of his books and are pure gold, his experience and knowledge are outstanding, and you can still see him coding!
- Old blog http://butunclebob.com/ArticleS.UncleBob (it has some very interesting posts)
- New blog http://blog.objectmentor.com
- Clean coders http://www.cleancoders.com/, a bunch of great software development resources
One of the heads behind StackOverflow, a hardcore developer that has been doing really cool things for more than a decade. His blog posts are extremely interesting and very, but very useful.
- Blog http://www.joelonsoftware.com/
- Hg init tutorial http://hginit.com/
- The Joel test
- StackExchange http://www.stackexchange.com/
Another of the heads behind StackOverflow, a very skillfull developer that has been delivering lots of tips, principles and advices for years.
- Coding horror http://www.codinghorror.com/blog/
- StackOverflow podcast http://blog.stackoverflow.com/category/podcasts/
Miguel de Icaza
He is the mind behind the initial Gnome project, started with Mono and now it's driving his own company called Xamarin. He might be controversial at times, but for sure it is worthy to follow him.
One of the most productive developers I've seen, he's a .Net evangelist with years of expertise. His projects and blog are just amazing. Besides that he's a podcaster with various memorable recordings.
- Blog http://www.hanselman.com/blog/
- Hanselminutes http://www.thisdeveloperslife.com/
- This developer's life http://hanselminutes.com/