Web Site Development Environment Recommendations

I frequently get asked what I use to develop my clients' web apps or if I could recommend a tool to do such-and-such. It's a good question. Web development is constantly evolving as quickly as the web itself. With so many choices, it's easy for new developers to get overwhelmed, and harder still for experienced developers to stay on top of the tools.  What follows is a list of tools and hardware I use to create complex custom web applications for my clients.