Eclipse Eclipse Eclipse... It's the only way (TM). I used to try every IDE that came out and all sucked for different reasons. Since I started working on Eclipse, I haven't even looked for another. It does native rendering, so it's many times faster than JBuilder, plus it has all the core technology from VisualAge (local change history, incremental compiling, etc). CVS integration is great. It's open source. It runs on just about every platform you can imagine (while Eclipse itself is 100% Java, it uses SWT, a "replacement" for AWT that provides a lot of compelling features, thus the SWT backend must be ported to your platform-of-choice for Eclipse to run).
I recommend downloading the 2.1M3 stable release (even though it's not final, it's enough better than 2.0 that it's worth using).
Mike