Baen free library got me started, then I started stumbling over free books in .lit format. Eventually bought the Jetbook then a Jetbook Light.
Now my current collection is over 14 gig and 23,000 books with over a thousand authors. Possible there is some amount of duplication in that. As it has grown beyond my interest in keeping it straight. Will I read them all, no, not likely. Am I trying, well, sorta.
I certainly love having the option to try.