In times past that kind of question would have started a flame war.

There are many to choose from and many people use more than one editor depending on what they are doing.

For myself, I tend to use eclipse (with the EPIC plug-in) for large projects, and one of Padre, gedit, kate for simpler scripts. For quick edits I often dive in with nano.

Don't take my choices as gospel, there are plenty of other alternatives. Listen to the other suggestions here, and try many different editor before you make up your mind.