The best IDE for Erlang is Emacs. However, the mode which ships with Erlang isn't the best. Erlware-mode extends it and Distel allows you to use Emacs itself as an Erlang node, enabling some very nice features. See this blog post.
Between plugins for NetBeans (ErlyBird) and Eclipse (ErlIDE), I prefer the Eclipse one. NetBeans at least used to require nightly versions of NetBeans and didn't work properly for me.
Pros:
Syntax highlight, autocompletion and suggestion all work well.
During suggest it will display some documentationif available: very useful when exploring a module.
Error and warning annotiations are quick and helpful.
All things considered the user experience is good, especially if you are used to eclipse.
Cons:
Erlide can also run your modules, but I find the shell is too clunky to be usable. I always keep a "real" erlang shell open and compile/test my code from there.
There is also a Textmate bundle (google), but I have not tried that yet.
if you are a new emacs user, i think emacs can really kill you :(
i try erlide(buggy for jump to defination, other is good) emacs-erlang mode(really hard for me), i finally choose sublime text2 for daily development. i suggest you can try it.
i install the following plugins: package control sublime-erlang sublimerl ctags