Microsoft developer tools are the best for programming. They make developer job very easy and convinient. But they do not offer everything you need to accomplish your task in the best possible way.
Here some very useful developer (free) tools which can make the programming more convinient.
Simulating and testing Soap web services. soapUI is a tool for functional testing, mainly of Web Services like SOAP based Web Services and REST Web Services, but also HTTP based services and databases.
More Info: http://www.soapui.org/
Explore and analyze compiled .NET assemblies and viewing them in C#, Visual Basic and IL. Converts compiles assembly code into C#, Visual Basic programming language code.
More Info: http://www.red-gate.com/products/reflector/
Very useful tool if you are viewing/monitoring log files. Configurable text highlighting and real time file viewing.
More Info: http://www.baremetalsoft.com/baretail/index.php
More Info: http://www.my-debugbar.com/ietester/index_all.php
SQL Data Compare
SQL Data Compare is a very useful tool to compare and synchronise databases. This would compare two databases, individual tables and rows in each table. This would give good knowledge if you want to understand what happened to data before and after a complex SQL transaction.
More Info: http://www.red-gate.com/products/SQL_Data_Compare/index.htm
XMLSpy is an advanced XML editor for modeling, editing, transforming, and debugging XML-related technologies. The XML editor delivers the power you need to create the most advanced XML and Web applications.
More Info: http://www.altova.com/xml-editor/
Another great subversion client. Acts as a front-end to Tortoise SVN for all your projects.
More Info: http://www.svnmonitor.com
NDoc generates class library documentation from .NET assemblies and the XML documentation files generated by the C# compiler. NDoc uses pluggable documenters to generate documentation in several different formats, including the MSDN-style HTML Help format (.chm), the Visual Studio .NET Help format (HTML Help 2), and MSDN-online style web pages.
More Info: http://ndoc.sourceforge.net/
Another documentation generation tool. GhostDoc is an awesome tool that takes some of the drudgery out of documentation. It's an addin for VS and it's free; right-click on a method or property and it will parse the name and figure out the proper summary for you. It's pretty smart when it comes to inheritance documentation and the override methods.
More Info: http://submain.com/products/ghostdoc.aspx
LINQPad lets you interactively query databases in a modern query language: LINQ. LINQPad is also a great way to learn LINQ. LINQPad is more than just a LINQ tool: it's an ergonomic C#/VB scratchpad that instantly executes any C#/VB expression, statement block or program with rich output formatting.
More Info: http://www.linqpad.net/
NAAK – the .NET Accessibility Analysis Kit
NAAK is a .Net control which can be placed bottom of each page in your web application to notify you of any known accessibility issues. This helps ensure compliance in two ways. First, it clearly exposes accessibility issues to each developer, QA analyst, and application reviewer. Second, and more importantly, because it is returned as HTML with each page, it can be checked using any web user interface testing framework.
More Info: http://code.google.com/p/naak/
Blueprint CSS Framework
Blueprint is a CSS framework, which aims to cut down on your development time and eliminates the discrepancies across browsers. It gives you a solid foundation to build your project on top of, with an easy-to-use grid, sensible typography, useful plugins.
More Info: http://www.blueprintcss.org/
More Info: http://getfirebug.com/
More Info: http://chrispederick.com/work/web-developer/
Internet Explorer Developer Toolbar
More Info: http://www.microsoft.com/downloads/en/details.aspx?FamilyID=95e06cbe-4940-4218-b75d-b8856fced535