Text editor capable of viewing invisibles?

Question

A recent problem* left me wondering whether there is a text editor out there that lets you see every single character of the file, even if they are invisible? Specifically,

Answer 1

In Visual Studio's Open File dialog, the Open pushbutton has a down arrow next to it that lets you choose Open With.... One of the options in the resulting dialog is Binary Editor.

I've used this now and then to spot some invisible character or to resolve some line-ending issue.