What is the Preferred eBook Format to unDRM ebooks for iPad?

[okolowicz]

Unless I'm blind, I haven't been able to find this question answered despite rigorous searching. Needless to say, I think the question speaks for itself but here's my situation:

My primary reading device is now my iPad. Usually, I stick to buying Amazon Kindle books because they can be used on all devices with the Kindle app but there have been instances when I've bought books through iBooks and B&N due to availability or price. However, I prefer having all my books in the same location/app on my iPad.

Maybe I'm anal but it was annoying when I had some books in iBooks, some books in Kindle and others in the B&N app. Furthermore, my wife also uses the iPad and we prefer to keep our "libraries" separate. Therefore, I currently keep my books in the Kindle app and all her books in iBooks. This way each of us can easily go to one place to find all our books without the clutter of the other person's stuff.

Generally speaking, removing the DRM from Kindle books has been painless. However, I've read that removing the DRM from Topaz books can wreak havoc on pictures. Most of the books I read do not have pictures, therefore, I've yet to come across this. However, this dilemma brought to the question at hand: When buying ebooks, is there a preferred vendor/format I should be buying to have the best results when removing the DRM?

I get most ebooks from Amazon (including free Amazon ebooks). I download them using Kindle for PC, then remove DRM protection using a Calibre plug-in, and then transfer to one of my Kindles or my Sony Reader. Thus I know that I won't lose any of my ebooks and I will be able to read my ebooks on any device in the future.

I'm not sure about iBooks, but I don't see many problem removing DRM from .AZW and .EPUB ebooks from Amazon, Barnes and Noble now that we have great and free Calibre DRM removal plug-ins.

There are much more problems converting PDF ebooks, since there are different kind of DRM protection. While you should be able to remove DRM from Adobe Digital Editions .PDF files, there can be problems with PDF ebooks using other protection mechanisms. Also I don't like PDF files, because it is more difficult to convert them.