Gedit is the default text editor provided with Gnome in Ubuntu and other distro. It look very simple, but it extensible with plugins.
Here a list of some cool features and styles you can add it.
This Howto is for Gedit >= 2.20 for an older version take a look here.

Session Saver: you can save the status of the tabs/files opened
Snippets: use quicly the most useful piece of code
File Browser Pane: a mini file browser embedded in the editor
Code comment: a shortcut to comment your code. Many languages are supported
You can install them with:
sudo apt-get install gedit-plugins
Snapopen http://www.upperbound.net/snapopen/
Class Browser http://www.stambouliote.de/projects/gedit_plugins.html
Word Completion http://elias.hiex.at/gedit-plugins/
Unpack the files in ~/.gnome2/gedit/plugins
then open gedit and enable the plugins you need from Edit > Preferences > Plugins
Other plugins are avalaible on the wiki.
The syntax highlight of .rhtml, .html.erb, .rjs,.. is avalaible with these easy steps:

wget http://robzon.kapati.net/rails/rhtml.lang && sudo mv rhtml.lang /usr/share/gtksourceview-2.0/language-specs/
wget http://robzon.kapati.net/rails/rails.xml && sudo mv rails.xml /usr/share/mime/packages
Mi dicono..
3 hours 11 min fa
20 hours 28 min fa
23 hours 36 min fa
1 giorno 20 min fa
1 giorno 34 min fa
1 giorno 3 hours fa
1 giorno 8 hours fa
1 giorno 13 hours fa
1 settimana 2 days fa
1 settimana 4 days fa