Originally Posted by ereaderundecided
But would if I don't want to convert and use an app, which one is most common or popular?
Google for a device that includes ePub then and take your choice.
Start at the top of the results list for "most queried".
Plus a reader application that handles ePub:
If instead of the above device you want one of the models that includes a keyboard, then:
Also does ePub.
This question is really a personal decision which you should make for yourself.