My favorite IntelliJ feature is that it tracks the full history of the files in your project, losslessly and independently from your VCS. You can just go and pull source from Local history, from 5 minutes or 5 days ago (I'm not sure how far back it goes, I've never needed more than a week).

Not something I use often but as a last ditch effort to find code that I've spent hours or days on and subsequently lost to a git mistake, or reverted thinking I was going to use a different approach, it's worth the price of entry for the JetBrains tools alone.