Generally I read A LOT of fantasy/dystopian books. If I need a break and want to read something that I know I will like regardless? Give me a book a-la Stephanie Perkins. I love the cute fluffy ones that give you hope that there are awesome people out there that will do almost anything for the one that they love. (See youtube video of the lip dub proposal, he fits into this category, too.)
I agree with Maggie. I need something light-hearted and fun, but something that has a very definite love story, where we know there will be kisses and I am certain of a happy ending. And generally, this would all coalesce in a YA book, but sometimes, a good old-fashioned chick lit book will do the trick, like a couple I’ve read several times & have talked about here ad nauseum, Just One of the Guys by Kristan Higgins and The Cubicle Next Door by Siri Mitchell. Neither of these are particularly without a little drama and darkness, but their love story is uplifiting and leaves me with a big ole’ smile on my face.