"A book you've wanted to read for a long time but still haven't"
Blue Bloods Series by Melissa de la Cruz. I got the first three together cause they sounded fun, like Gossip Girl with vampires. I read the first book and liked it a lot. The first book was fresh and original, I'd not seen anything like the way it mixed vampires and angels and the Manhattan, Upper East Side angle made it all the more fun. I do have the entire series and novellas in paperback, but for some reason never seem to get around to reading them.
Dark Tower Series by Stephen King is another one I've been wanting to read. When I started reading King's books it never appealed to me, cause it wasn't flat out horror. But as I've read more epic fantasy novels over the years as I've grown older, its become more and more appealing. I got the first seven books on iBooks for Christmas a few years ago, and still haven't managed to read any of them.
Loving the first book and then going out and buying the rest of the series but taking forever to read them seems to be something I do a lot.