OpenJDK is default in Ubuntu now, which works fine for most things.
Unfortunately, I do a ton of remote desktop work via a Sonicwall SSL VPN 2000 device. This portal has a really cool page that allows you to run remote desktop over links right from its webpage, but it crashes firefox when closing a remote session with OpenJDK on ubuntu.
So I have no choice but to run Oracle's Java.
To do so, open a terminal then enter:
sudo apt-get purge openjdk*
sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java7-installer
you should then be running full on Oracle Java, and firefox won't crash any more with SSL VPN remote desktop links.