This I've done with dozens and dozens of books - technically I'm still reading Anna Karenina, but I think it's been a year and a half or so since I last opened it, so when I feel up for it I'll just restart from the beginning. That one I own, but mostly this happens with library books, and at some point I just bring them back, and maybe give it another shot later. Like many other people, I started and gave up on Steven Erikson's Gardens of the Moon - twice even, I think - but then tried again, got through it and liked it enough to read the awesome next two books, and the rest of the series.

And it's not even necessarily that I dislike those books, usually I'm just not particularly gripped by them. Or I do love them, but find them too exhausting - Thomas Pynchon's books Mason & Dixon and Against the Day fall in that category. Still want to read them, especially the former, but they're books that are very hard to read at more than twenty pages a time, and after a while I just gave up.

I don't really remember having given up on books in disgust, no... but yeah, loads of books that I haven't finished.