I currently do the vast majority of my programming in Java - I plan to release a project here on the Early Dev forum in the near future which I've written entirely in Java.
Now, I haven't really had much experience with different sorts of IDEs, but I primarily use Eclipse for Java, and I find it meets my needs exceptionally well.
I am also in the process of learning other languages - Python and C among them - and while I tend to use Notepad++ for anything I do in C, there is actually an IDE available for Python called PyCharm. I have limited experience with it at this point, but it appears to have at least the same fundamental features for Python that Eclipse has for Java, although I'm still navigating the differences.
As far as languages themselves go, I'm not at all comfortable with Python yet - I, too, dislike the lack of explicit declaration of variables that was mentioned by a previous poster, and I also don't really like the inflated importance of formatting - in Java, it's a convenience, but in Python, it's an absolute necessity, and some of the habits I've gotten into with Java don't really align well with what Python demands. I'm much more interested in C - it shares many similarities with Java, and while you can make mistakes that simply aren't possible in Java, you also have that same margin of increased capability.
Maybe I will eventually come around to Python, but for now, I'm not a huge fan.