I use eclipse+pydev(and c extensions, just started learning c) and I like it. I am also testing Pydev extensions. One reason I use Eclipse is that I can embed Vim in it. It also has couple vim wrappers. (Although Netbeans has couple vim wrappers too)
I did check out Netbeans, it is actually very nice however there is a weird bug that stopped me moving to it. It highlights the words that is next to the caret(in Python projects). I can see the merits of this behaviour but I do not like it because I use darker themes and the selection just sticks out. I think this behaviour is hardcoded in the python plugin because in C plugin you can disable it. Notepad++ has highlighting occurences as well but it would highlight only when the user selects the whole word manually. This thing selects the word and highlights automatically.
The other thing I did not like about NetB is the way it is handling C projects. it lets you compile a single file but it wont let you run within the IDE which is weird. It is either not implemented or not working properly. Since I am a C beginner, maybe someone can explain how I should work with in NB.
I tried Komodo IDE and Edit, they are both very nice(one is free), definetely IDE version is very well integrated and has advance functions. I just cannot justify the price for my little projects. Komodo Edit does not have proper Python shell which is a big minus.
One other alternative is Pyscripter. That one is great and nice but it does not let you have more than one project at a time. On the other hand Eclipse+Pydev offers many projects options.