I’ve been using Resharper for a while now, in fact ever since it has its first public EAP. At the time it came like a breath of fresh air. I’d been used to using Jetbrains’ other development productivity tool, IntelliJ IDEA, as a Java coder and the single most painful thing about .NET coding at that time was the lack of a decent automated refactoring tool and code navigator. Resharper went a big step to filling this gap.
3 years on or so and I still think Resharper is the number 1 must-have Visual Studio plugin. If you are writing for C# for a living, I believe it pays for itself within days. It doesn’t just help by making coding faster, it allows you to actually code in a different way by allowing easy traversal of delegation trees; encouraging simple, quick, automated refactorings across your entire source tree; and a whole lot more besides.
Resharper version 2 had a few speed bumps for some people, but version 2.5 is out now and apparently goes towards fixing those problems (I’ve managed to keep the solutions I’ve been working on this year lean and nimble, so haven’t had these problems, but I know many people have.) If you’re a C# coder and have never tried Resharper I can’t recommend it enough.