Might be a little difficult to find in print if you like physical books, but the Paratwa trilogy by Christopher Hinz is probably my second favorite series ever (behind The Black Company). First book is called Liege-Killer, and the premise is that back in the last war that made Earth mostly uninhabitable, they used genetically engineered assassins called Paratwa, a person that has two bodies but one consciousness. I mean literally one being that just happens to be in two places at once, like your right hand and your left hand working in unison without you having to even think about it. This made them the ultimate killing machine, masters of disguise and infiltration, etc. and often used to kill (and often assume the identity of) prominent figures. Reemul, the Liege-Killer, was the one that was sent out to kill other rogue Paratwa, so obviously he was the baddest of the bad. Supposedly most/all of the Paratwa were destroyed decades ago, but someone secreted Reemul away and put him in cryogenic stasis, and now he's been awakened to a world not used to Paratwa. Dun dun dun!!!
There is quite a bit of political intrigue and maneuvering mixed in with the all-out carnage of the Paratwa, along with a fairly unique take on what life would be like in such a world. I've read the book probably five different times at least, and the entire series three times I think. I have recommended it to like ten different people with varied tastes over the years, and every single one of them has liked it and wanted to read the other two books. So if you like sci-fi at all, I don't think you'll be disappointed.