BPBible is an incredible free, open-source application that makes studying the Bible a breeze.
The BPBible interface is quite complex. The good news is that you'll be able to find your way around fairly quickly and the whole thing is entirely customizable, which means that you can remove any windows that you don't need.
One of the few problems with BPBible is something that you are going to notice fairly quickly. You must download content for the program before you can view anything using it. It doesn't come with any preloaded content, and when you do go to download you are limited to the files provided on the BPBible Portable website. Because of this, it might be worth taking a look to see if they meet your needs before downloading the program.
Once you've got your bibles sorted out, you can get down to studying them. You'll have no problems in this respect, because BPBible has more features than you would ever need. You can look up your dictionaries, swap between texts, add comments, browse verses, tag text and even play a game.
BPBible has several features that deserve special attention - cross-verse searches make looking for phrases and ideas far more intuitive, while the topic management function allows you to tag and mark selections and open them in an integral manager for organization and modification.
Finally, if you are feeling flexible, BPBible will also choose random verses for you to study. As you'd expect, all of the aesthetic parts of the program - font and size, quotation style etc. - can be customized as desired.
Bear in mind that BPBible is also available as a portable, no-install program.
BPBible make Bible study intuitive, flexible and customizable - what more could you want?!