You have used many text editors for writing code and other snippets like Notepad++, jEdit, gedit etc but i found an amazing text editor Sublime Text 2 that have lots of features like syntax highlighting and auto complete. Sublime Text 2 fulfill all basic needs of developers and increase their proficiency. It supports likely all programming languages and lots of plugins are available to enhance its capability. I think Sublime text 2 is best text editor for developers.

Sublime Text 2
Basic features of Sublime Text 2:
- Cross platform(Windows, Mac, Linux)
- Instant project switching
- Very Fast and Light
- Search Packages and Features (CTRL+P)
- Two color schemes Dark & Light
- Auto-complete feature
- Distraction-free mode
- Plug-ins Support
→ You can use Sublime Text 2 for free but full version license cost is $59/user.