I have been using Eclipse more or less heavily for the past 10 years now.
For my last project I decided to give IntelliJ a spin. And as it turned out, I like it! IntelliJ does many things a little bit better than Eclipse.
This list should highlight those ‚little things‘:

1. Maven Integration
   • Maven Integration works smoothly, unmatched by Eclipse
   • Maven is mostly hidden from you
   • If you have to use maven, there is comfortable tools support
2. Jump to test
   • Quickly see related tests for a class
   • Nice companion for tdd
3. Find resource
   • Nice in Eclipse, this really feels like Spotlight/Alfred on Mac
4. Live templates
   • Quickly generate boilerplate code
   • More poweful than Eclipse
   • Extensible
5. Code Completion everywhere
   • Even in the debugger view!
6. Facelets editor Smooth code-completion based on taglibs
7. Spring editor: Show resolved property from config
8. Team city integration: Pre Tested commits/Run test locally
   • Keeps your repository clean
   • Less broken builds
   • The option is quite hiddem
9. Subversion: Show Outdated version while editing
   • Quickly see you might want to update this file
10. Analyze
    • Quickly do a static analysis of your code
    • Built in
11. Handy shortcuts to extract an expression to a variable/method, or class
12. Variable name guessing mostly works
    • If you assign a method to a variable for example
13. Bind constructor parameters to fields
    • And create getters/setters on the fly
14. IDE Chat: Quickly send code pointers to your team mate
    • Based on jabber
    • Worked out-of-th box, no need for a jabber server
15. SQL Editor: Run SQL to:
    • Surprisingly good
    • Tools like SQLDeveloper are needed only occasionally
16. Code folding using anonymous classes
    • Almost feels like closures (#prejdk8)
17. Encoding Support: – Properties (native to ascii)
    • no \u…
    • Notices you if the encoding of your file is wromg
    • Helpful info in the statusbar (a little small though)
18. Deployment
    • Run script beforehand or after deployment
    • Possible to manually tweak artifacts
19. Server Support
    • Set PATH variables
20. Structural Select (Ctrl-w)
    • Do complex search and replaces
21. Fun!!
    • Yes experimenting with IntelliJ was fun
    • Less cursing than eclipse
22. Add Missing Switch Branches
    • When using enums
23. Very good diff tool
24. Fast svn updates via patches
25. Fullscreen Support
26. Darcula Theme
    • I like it, some don’t
27. AspectJ Support
    • Show active aspects of a method, or related methods to an aspect
28. JPA Support
    • JPA console (Send JPA queries, to the DB)
    • See connection of JPA class to DB table (complains, if theres is none)
29. XML Editor
    • Very good XPath support (Show XPath of this node, apply XPath on document)
    • XML Refactoring
30. Refactoring Support für POMs
    • Looks for changes in other pom-files
31. Emmet Support
    • Nice and handy
    • http://emmet.io/