Looks like you still got about 10 different kernel versions installed.
First try to de-install the older kernels versions with
apt-get remove linux-image-3.8.0-xx-generic
with the revision code, like 19, 22, 23 and so on.
Starting with the oldest version and working your way up until you only have the latest 2 or 3 kernels left.
You might still get some error messages because apt-get will try to rebuild the initrd.img files every time and there might still not be enough free space at the beginning.
It should go better after you removed a few of the older kernels.
For people reading this thread. Normally you only need to keep the last 2 kernels. The one you just installed. And the previous one as a fall-back in case the new one gives you problems.