cobol
Is the reason I nearly dropped out at Uni my first year. At 18 I could eat Pascal, Delphi, C variants for lunch, but that SHIT had me pulling my hair. There's still tons of legacy code running at finance/insurance firms. My uncle was still banging out COBOL till 2 years ago. It's mostly just your older programmers that's comfortable in COBOL. When I was still writing code for a living C# was becoming popular so we used that a lot. Or Java.
C variants you'll only use when doing hardcore engineering where you need tight control and code straight to the metal. If you're going to do fancy UI stuff where tight control don't matter as much, C# or Java. IMO