This is my current configuration, placed here for my own future reference but also for sharing. I really appreciated others sharing their i3 configuration on github, so this is my turn to do it.
I wanted a clean looking terminal (urxvt) nice fonts in Firefox and a minimal but informative statusbar. The Firefox fonts where a bit of a challenge, as it tends to switch to ttf-embedded bitmaps. But now it's sorted out using fontconfig - see the relevant configuration files. The fonts listed in the configuration files must be installed on your system.
Here is an usage example:
cd ~/.config
git clone https://github.com/valir/i3-config.git i3
ln -s /home/<youruser>/.config/i3/fontconfig .
ln -s /home/<youruser>/.config/i3/dunst .
ln -s /home/<youruser>/.config/i3/gtk-3.0 .
ln -s /home/<youruser>/.config/i3/gtkrc-2.0 .
ln -s /home/<youruser>/.config/i3/gtkrc .
ln -s /home/<youruser>/.config/i3/.Xdefaults ~/
# now reload your i3 configuration
Have fun!