I like to do a lot of research and then buy the book outright. I mostly read standalone novels even though my favorite two genres are sci-fi and fantasy. Also, I am a slow reader. The only times I will buy multiple books at once is when not doing so will cause me to not get a matching set of books. I much prefer hardbacks or at least trade paperback over paperback copies.

Also, I tend to give books away when done with them. I don't want a huge collection of books for when I move.