Here are some of the IDEs that i have tried and I liked.

Geany - simple editor, loads fast, has interesting features like code completion, syntax highlighting. Works well with Python 3

NetBeans - very good IDE. I am using it currently to develop a sophisticated website. Works well wit large projects. Drawback: no word-wrapping feature.

CodeBlocks - I am using it for C,C++ projects at school. Very good IDE, with a simple and intuitive interface. It has syntax highlighting, code completion and fast compiler.

GEdit - default text editor in Ubuntu. Works with any type of code. Best for fast code corrections.