Total Eclipse of the IDE

I try to keep an open mind about the tools I use to develop software (it helps that one of my personal value statements is "diversity over uniformity".) In my experience each IDE, compiler, framework, language and so on has both strong points and weaknesses. But I do find it helps to deliberately try a new or different tool from time to time and reflect on what I learn from doing so. So in that vein I offer this little snippet from my own experience - not wanting to participate in any "religious wars" between IDE devotees :-o
One of the nicest things I have found about working with Eclipse is that it allows you to forget about compilation problems. You can happily write and run JUnit tests when your code won't compile, even tests that reference broken classes or methods. This feature really resonates with me because I can proceed through multiple test-code-refactor cycles with just baby steps, where other IDEs would make me go off on a long detour to fix all the compile errors before I could even run the test I wanted to focus on. In situations that require several refactorings to introduce a new feature, keeping the ability to concentrate on one thing at a time is just what I need.
Reflection: Which IDEs have you used? What do you like or dislike about each one? What are the particular circumstances in which one would be preferable to another?