Kev's space-invaders is very popular. You can get it on:http://javagamesfactory.com/articles-content.html
...along with a few others. The tutorials section has largely stagnated in the last couple of months because:
1. I've been busy working on the complete re-design of the site, so there's been no-one to actively seek out tutorials
2. With the current (old) site I couldn't appoint tutorial-editors to do that themselves. One of the major advantages for the new one is that I *can* delegate this 100%.
What that means is that once JGFv3 goes live we'll go on a quest for more java game programming tutorials to add. We've also been gathering links and texts for a section of "tutorials we found elsewhere that are really good" but that's fragmented into various files on my hard drive right now so I can't easily copy/paste it for you.
If you get stuck, try gamedev.net. It's java tutorials suck, but the general games programming ones are often quite good. And there's a heck of a lot of them.