JetBrains has an amazing set of IDEs right from Java to Python to Ruby and so on. They are a bit expensive though. For example, IntelliJ IDEA personal license can be bought for $199. But today, JetBrains is offering a steep discount of 75% on all their products which include IntelliJ IDEA, PyCharm and a host of other awesome IDEs.
It is a limited period offer and to be precise its an offer only for 24 hours on 20th December, 2012. So, what are you waiting for? Head over to their website and NOW!!
EDIT: This offer expired on 21st December, 2012.