Iain M. Banks’ latest book (I think) Transition is pretty great. It’s about a multiverse hopping assassin who’s on the run from the organization that he works for. Remember Sliders? It’s sort of like that but there’s no big portal that they jump through, the Flitters have more control over where they end up (and can go home again) and they arrive Quantum Leap-style, in someone else’s body, worn like a disguise.
But it’s more than old TV shows. The book’s really about competing philosophies of life and solipsism and the possibility of doing good in an infinite existence. There are completely self-absorbed characters and completely delusional ones and one is a torturer (from a world where militant Christians were suicide bombers in Thatcherite London, prompting a huge scale war on terror and abrogation of civil rights). There’s lots of sex and high adventure. Heartily recommended.