IDEs:Eclipse - My current workhorse. OK for the both the C and Java I do.
NetBeans - My favorite Java IDE. Not that good with C though

Visual Studio - My favorite overall IDE. Don't use it anymore since there's no Linux version
Editors:gedit - Simple, easy, comes with GNOME.
nano - Simple, easy, not mentioned in flamewars.
vim - I don't like it (or emacs

), but will use it in a pinch.
Misc:GIMP - Makes bitmaps...
Inkscape - Makes vectors...
Audacity - My general-purpose audio workhorse.
LMMS - For when I pretend I can make music.
Renoise - For samples that LMMS doesn't have.
JigPu