I don’t like linking to every single tool that comes my way. The question I always ask myself is “If my laptop crashed would I look for, download and install this tool again?”
There are tools that are so unassuming and so obviously make sense, and I have to recommend Rockscroll that Scott Hansellman has so kindly provided for the world outside of Microsoft.
In an ideal world a C# class would fit onto your screen, since it should be short and functional. However in the real world you are going to inherit bad code, and also look at generated code from time to time. You can easially spend your day navigating this one monster file. Hence Rockscroll:
This is also good for those really long SQL files and Powershell scripts.