If I'm doing 2 playthroughs, usually the 1st will be total asshole. I find it funny, in games where you are the protagonist, how you even set about the main goal of the game in the first place, when it usually involves bringing peace, or saving some people. The writing is usually more interesting an unpredictable in ways that you can needlessly fuck people over, rather than just save them and not accept any money for it.
True, the good route usually pays it's way somehow. Also true, that many of the evil choices are predictable as well. But when you are given the option to *really* go out of your way to screw people who are already down, is where it gets interesting. When it comes to companions though this is tough, because you want them to have your back at the same time, unless you genuinely are trying to get them all killed in the process.