I'd agree with some of the others out there saying that NetBeans and IntelliJ are both good IDEs. And I'd say that in using all three (Eclipse + other two), that Eclipse is by far my favorite. I found some of the documentation out-dated, but also found the support community very helpful. I started using Eclipse by jumping into the deep end of the pool: writing an RCP before ever learning the IDE. The IDE was intuitive to use, and when I found the right news groups to post to - most of my questions were already answered. The hardest thing for me (and frustrating, admittedly) was knowing how to phrase my search terms in order to get to the answer that was already posted.
Remember that Eclipse is still "relatively new" as an IDE player, though given that - it's pretty darn robust.
My only complaint about Eclipse is that with each new release, it seems to hog up more resources. With a mid-sized project/workspace, it takes seemingly forever to build (or rebuild) the project. Compared to IntelliJ, it's faster and more intuitive to use.