I have been using PyCharm for the past few weeks now, and boy its sleek ! However, there is another Python IDE launched recently called Spyder which looks promising too.
Spyder (which has been around since 2009) on the other hand is an Interactive Development Environment focusing mainly on scientific computing and interactive data analysis and exploration, with lots of handy tools for poking around in and plotting data.
Both are great, but they target different uses and complement each other rather than directly compete.