PDF Reader
Adobe Reader
wget -c http://ardownload.adobe.com/pub/adobe/reader/unix/9.x/9.5.5/enu/AdbeRdr9.5.5-1_i386linux_enu.deb
sudo dpkg -i AdbeRdr9.5.5-1_i386linux_enu.deb
If you use 64-bit Ubuntu, you need install the following dependencies:
sudo apt-get install libxml2:i386 libstdc++6:i386
Now, you can run Adobe Reader by typing acroread in the terminal.