Please also mention the reasons

hi,

I prefer netbeans when comes to open source IDE because of ease of use and rich functionality when compare to paid versions.

Second preference will be Eclipse if you ready to pay for license

hi....Netbeans is easy to use....but eclipse helps u to lot..becoz most of the companies use eclipse,
so start using eclipse helps u lot in future.

Netbeans provides good drag and drop options for java desktop applications development. But as some one said, eclipse is better especially for web applications, As there are lots of free plugins out there for almost everything you want to do. Eclipse is more popular so developing complex apps will be easy by using third party APIs.