He's asking about STORAGE formats....
And storing your images in RAW is pretty silly. I see zero reasons to do so, really, and many reasons not to.
If you want to store the full bit depth, etc., then use DNGs or higher than 8 bit tiffs or pngs or whatever.
These will do the same thing as RAW and MORE, because RAW is a proprietary format that usually doesn't support all kinds of edits (like transparency, for example). Some I don't think you can even save in at all, meaning you'd be storing unedited images.
Additionally, it doesn't have the same forward compatibility as normal file formats do. Some years down the line, you may not be able to open your RAWs if you've lost your software and whoever supported it or made it has given up. That's just ridiculous to risk, when you can store the same info in a common format that definitely will be supported in years, like DNG or tiff.
For real quality that you actually will ever notice and care about as a non-paranoid person, save in either:
* jpeg with a low amount of lossiness ("quality 10-12" or whatever) - Do this if you're done editing and don't plan on going back and doing any more editing later. It has the highest compression and does so in a way that is best tailored to the human perceptual system (it compresses more where people won't notice it, thus most efficiently saving space without losing any real quality).
* or a 24 bit PNG perhaps (if saving directly from a RAW that was
never converted in between into jpeg or edited in 8 bits in photoshop, etc.) - Do this if you might still edit stuff later and still want more bit depth than the human eye can detect.
* DNG accomplishes the same thing as 24 bit PNG, but might be smaller files in some cases or more convenient for some people's work flow (since there's a nice adobe program that converts whole folders eaily with no fuss).
* or TIFF is okay if you really want or if a client requests it, but it isn't anything magical. It doesn't add quality. It just acts as a wrapper for holding more types of information (like vectors and crap), and it is a standardized container that some printing industry types prefer since it agglomerates many types of formats together conveniently. If you don't actually have any vectors or transparencies or weird stuff, though, it's probably mostly a waste of space.