This post is mostly so I can reference which extensions I regularly use. It can be a bit of a pain to try and remember the ones I don't use very often when I switch between my work and home PCs. It would be awesome if VS could sync my extensions and their settings. Maybe in VNext.
Just a quick note: I do not work for any of these companies. Where the extensions are not free I paid for them with my own money.
Must Have (every day use)
The first productivity tool I used for Visual Studio (way back for VS 2005). Yes, I've tried ReSharper. In fact, there was a time where I was using both CodeRush/Refactor! and ReSharper via some hackery. I've looked at other tools, but always come back. Not free, but worth the money considering you only have so many keystrokes before you die.
I also use the CompilationResult plugin to add a little humor to my life. Green encouragement messages when the code compiles, Red humiliation messages when it doesn't. Always fun when presenting.
Bonus info: DXCore is a free plugin framework and the Compliation Result plugin works with it.
Everything Mads does is magic. Web Essentials is a playground where the Aspnet team tries out new functionality that may eventually be baked into Visual Studio. This is the second extension I install.
Before the Productivity Power Tools and Visual Studio added much needed enhancements to the tab well in Visual Studio there was Tabs Studio. I originally installed it to get better control over tabs in SQL Server Management Studio, but quickly began customizing the rules and options for VS (Source Control Explorer tab always left most ftw!). Not free, but reasonably priced considering it works will basically all versions of VS and SSMS.
Errors in red in the output window, yes please! Colorizing the output window is awesome, and should be baked in to VS. If you've ever tried to troubleshoot a binding issue in WPF you know how difficult it is to spot in the output window.
Lots of features, some make it into the next version of VS some don't. Updated fairly regularly with additional tweaks. My favorites: syntactic line compression, peek help/definition, and timestamp margin. Make sure to disable the custom document well if you're using Tabs Studio as they conflict with each other.
If you administer TFS, these tools make your job a lot easier.
Add web.config style transforms to any config file. I don't understand why this isn't baked into VS already. Unfortunately, this is the last version of the add-in unless something changes - see Sayed's post for details.
Lets you F12 directly into .Net Framework source! No more annoying [From Metadata] tabs that only show you signatures.
Another one from Mads, shows you errors and warnings as an editor overlay for the file you're working on. No more digging into the Error window.
Want to your .min file nested under the raw js/css? How about concrete implementation files under the interface? This guy lets you nest files in solution explorer like a boss! Has a bunch of rules out-of-the-box that handle pretty much all the situations you can think of. Mads is a machine!
Want nicer /// xml doc comments? Want the comments filled out based on the names of your classes/methods/properties? Does your company have a specific format for comments? This does it all and more. Free version handles all the basics. Paid version has additional features. I use the free version, but thinking about shelling some cash out since I use it all the time.
Do you use T4MVC in your ASP.Net MVC apps? If you do, this automates the right-click > run custom tool dance you always forget to do after saving changes to a controller or static resource.
Just recently installed this and I like it already. Gives you little "encouragement" messages when you save files. You can also add some skepticism messages to keep it lively.
If you're rockin' VS 2013 Ultimate you know how awesome CodeLens is. This adds an additional indicator displaying a simple color to represent the maintainability of the code by utilizing various metrics (e.g., cyclomatic complexity, line count, etc.). I find that if this guys shows red, I take a second look to see if I can refactor for cleaner code.
Adds a "My History" item to Team Explorer that will list out what you've been doing in TFS. Can't remember the ID's of the work items you were just working on, it will tell you without the need to run a query or go to your sprint board.
Ever created a new class, write a bunch of code, and delete it only to realize you need it after all? This little guy keeps track of everything you do locally and independent of source control making it best suited for the times you're slinging code and not ready to check-in yet. It works well for this, but it's also interesting to see how you work throughout the day.
Less Used but still essential
Ever wanted to be able to Add New Item > nuspec? This guy adds all kinds of new file template goodness. A lot templates here and all very useful for getting started with new technologies like Angular.
I don't always need to optimize images, but when I do, I use Image Optimizer. Right-click > optimize on single files or an entire folder. No surprise here, another one from Mads.
Have you ever been frustrated when pasting code from a blog into VS only to have the line numbers and weird white spacing come with it? Mads was, so he wrote this extension will fix all of that for you, automatically.
Recently added to my list
Does this sound familiar: you need to create a file, but VS doesn't have a template for it so you create it in the file system, show hidden items in solution explorer, and then hit include in project? This simple extension will let you create that empty file right in solution explorer without the hassle. That's right, Mads created this one too.
This one's interesting. Shows you code samples, while coding, in the intellisense popup. I simultaneously like this and get annoyed by it, but not so much that I uninstalled it. Worth checking out if you're constantly googling (with Bing!) to find out how to use some API.
Powerful routing tools. See all of your routes and try out changes to routes. I don't do much with custom routing, but when I have issues this comes in handy.
Generates Knockout view models from C# classes. Very cool.
Recently installed this one. Has some nice features for managing subscriptions and pushing updated work item type definitions to multiple team projects. if you manage a customized TFS project template, you will find this automates some of those tasks that you had to script.
Let's you easily switch between NuGet references and project references during development of NuGet packages. Just installed this one, looking forward to leveraging it soon.
Which extensions do you find invaluable for day-to-day development?