Clang's error messages are much better than GCC - it will even spell-correct your typos and suggest which symbol you actually wanted to type. Around 2010 Google switched to a hybrid Clang + GCC environment (the same source code would be piped to both compilers, the error messages from Clang would be piped back to the user while the object files from GCC were linked to form the final binary), and C++ developer happiness skyrocketed.
To be honest, I think gcc has pretty much caught up with clang with gcc-4.9 when it comes to error message quality.
I have a slight preference for the way clang chooses to highlight the entire AST parent node that it thinks is responsible for the error, but the approach g++ takes is perfectly clear.
