Sublime Text 2
You know you have found a good tool when one day you realize you can't fathom how you got anything done before you started using it.
I have been using Sublime Text 2 for the past 2 weeks and I am totally hooked. Everything about it has been extremely well crafted and it is a solid product. Some of my favorite features:
All of the configuration files are plain XML documents
This makes saving your settings a breeze. You just take a look at the program/plugin default settings and copy the setting you want to change into your personalized settings file. Then if you upgrade the program/plugin you keep your settings intact!
CTRL+SHIFT+P && CTRL+P
If you have ever used a quick launcher app for your desktop you will fall in love with these two shortcuts. The first allows quick access to any command in the menu or any plugins that you have added. The second uses fuzzy search to open files in your current working directory. You will never have to open another folder!
There are a lot of them! Code formatters, linters, snippet packs, UI enhancements, plugins to install other plugins... you completely customize the program to work for you. You should start with the Sublime Text Package Manager. It makes installing other plugins a snap. Sublime SFTP is also amazing.
Before the switch I would code in Notepad++ and Netbeans. Being able to have the snappiness of notepad with a lot of the helpful features from an IDE is a breath of fresh air. I highly recommend you download ST2 and give it a spin. It has a full featured unlimited free trial (as do almost all of the plugins). Work faster!