Best text editor with custom syntax

What is the best text editor with the ability to create custom syntax? I used notepad++, but the custom syntax was a bit limited and the plugins (namely textFX) had a few bugs to satisfy me. I heard about Vim and Emacs (which one is better?), but I want a FAST editor with many features.

Do you code with a text editor?

A text editor is where you can sketch out or write code. Whatever programming language you want to learn to code in, be it HTML, CSS, PHP, or Java, you'll need to ensure that it's written in a specific format for it to work correctly.

Vim and Emacs are fast and have lots of features, including syntax highlighting.

Personally I use Vim, but both of them are powerful editors. If you use Visual Studio the ViEmu plug-in is a very nice option as it allows almost complete Vim editing within Visual Studio.