This week's book giveaway is in the OCAJP forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide 1Z0-808 and have Jeanne Boyarsky & Scott Selikoff on-line! See this thread for details.
I use Netbeans. Helps me to be focused on the functionality of the application rather than worrying about the layout and other alignment related issues for the GUI. I feel using GUI builder for larger application is better. But for smaller, sample applications one can use Simple editor to build the GUI. Also Eclipse has lot of plugins for GUI builder- One of them which I have used is Jigloo.