Notepad++ - Notepad++ is a great editor for Windows. Since it is written in C++ though it runs very well under WINE. It has all the functions you can want built in to start, and can be expanded through Plugins to do even more. This editor is Free as well.
Sublime Text - Costs $59 USD. A nice text-editor that is cross-platform and super snappy. It allows plugins to be written in Python. There is a free trial (which there are no limits to use.)
Filezilla - Free and cross-platform.
Cyberduck - Free and only for Mac and Windows. A different look compared to most other FTP clients.
If you use Linux or Unix-based systems (such as Mac OS), the ssh command is available on almost every system.
Putty - A graphical SSH client. Free and cross-platform.
Sloppy - Sloppy is a proxy that is built to actually make your access to a site slower than your base connection. It is very useful for testing load speeds on a real machine with a lower speed connection. If you are a Debian/Ubuntu user then you also may want to check this post out for getting it to run properly.
Lemonstand - Built specifically to be a robust ecommerce framework. Costs $300 (Canadian (CAD)) but is an amazing solution to build an Ecommerce site from. Free developer licenses are also available to at least give it a try.
Twitter's Bootstrap - One awesome framework that has a responsive grid, plenty of CSS functions, and some jquery plugins. It is built using LESS by default instead of plain CSS, but you can use the standard CSS setup as well. Very powerful and easy to use with very good documentation.
HTML KickStart - A fantastic kit that has tons of things to help build sites quicker. It is mostly basic HTML elements with some nice themeing, but has things like CSS buttons and other placeholders for other content. Great for rapid prototyping or development.
Skeleton Boilerplate - A boilerplate for mobile friendly development.
Zurb's Foundation - is perhaps the biggest competitor to Twitter's Bootstrap. It contains many of the same things as far as CSS and jQuery plugins go, but it has a few items Bootstrap does not. This is recommended for advanced developers only.
Blueprint CSS - A nice CSS framework for creating pages based on a grid. Also, check out the Cheatsheet. On the Github Wiki for the project there is plenty of links to documentation and other tools as well.
960 Grid System - Another CSS framework for creating pages based on a grid. Perhaps not as intuitive as Blueprint, but very flexible.
Responsinator - A neat tool for showing off Responsive Web Design.
Responsive.is - Another nice utility for showing off RWD. Very similar to Responsinator.
Responsivepx - Perhaps the most robust responsive design tool for testing. This is aimed more at developers since you can set exact sizes whereas most tools give you some preconfigured ones (and may not even tell you what they are.)
Image lazy loading is one way to speed up your sites load time. This is especially helpful on sites that utilize large images to a page. One way of doing this is by using a jQuery plugins such as Mika Tuupola's jQuery lazy loader which will load images as they are needed in the viewport. Do test carefully (as you always should) since image lazy-loading could have adverse affects on your site.
If you run your own server such as using a VPS or having a dedicated box, then you are in a strong position to improve your site's speed at the server level. To be continued
Bitbucket - Git and Mercurial version control site. Offers some free private repositories for personal development.
Github - Git only version control, free for open-source apps. Paid tiers offer private usage.
Generating Excel sheets from a MYSQL database - A tutorial for creating a script to pull data from a database and create an amazingly powerful excel spreadsheet for the output.
Login and Register Form with HTML5 and CSS3 - Tutorial on creating a very spiffy login and register form with HTML5 and CSS3.
Noty - An awesome notification generator. Requires JQuery.
Raty - A nice rating UI using JQuery. Fairly customizable as well.
Filtrify - A nice addition to sites that need some kind of filtering functionality. Uses JQuery and HTML5's “data” attribute in order to create filter helpers.
Quicksand JS - This is a nice JQuery based display of items (and sorting.)
JQuery Pagnination plugin - Lets face it, we are all tired of the same old static pagination. This tool that is a plugin to JQuery makes a much nicer experience with these setups.
CSS3 dropdown menu - A very nice CSS3 dropdown menu. Works well with multi-levels and some JQuery for IE6 (So you don't actually need JQuery anymore.) This is a great base to start working with for menu's.
Color Scheme Designer - A nice tool for getting a color pallete together for a project.