This one’s all about Richard K. Morgan’s neo-noir sci-fi novel Altered Carbon.
(And, yes, this is all a lot in one day, but I got a little sidetracked and haven’t been updating here for a while.)
This book is set in a future (a bit like Cory Doctorow’s Down and Out in the Magic Kingdom) where people regularly back up there brains and have them “sleeved” into new bodies, sometimes other people’s bodies. Things get wacky, as you might imagine, and pretty brutally violent. A pretty compelling read, though.