Steal things !
If you are planning on going evil, then you should be walking around town ready to steal everything you can. Unlike Oblivion, Fallout 3 doesn’t flag items as stolen, so you can clear out the shelves of many stores and sell the owner’s goods right back to him. Find a way to hide behind the counter to pick cash registers and even their safes. Once you get a few thousand caps in your pocket you can be a little more choosy in what you bother to steal and fence, but the important part about this too is that you don’t need any stealth skill to steal something – all you have to do is force the situation where anyone around has their back to you. Just keep an eye on the indicator at the top of the screen when you’re doing it.
Kill people if they have stuff you want
The Capital Wasteland does not a have a criminal justice system, so you can use this to your advantage and just kill some people for their stuff. Sure, if you start a fight with Lucas Simms then the whole town will try to kill you, but if you meet one of the wandering traders and want to loot all the crap out of his Brahmin’s packs, just kill him and his guard and take what you want. Be careful, though, as you can permanently break quite a few quests with careless murders. Either way, always keep in mind the question: « What if I just shot this guy in the face repeatedly until there is no face anymore? » You may find yourself killing the kind of NPCs you never even try to mess with in other RPGs, and seeing some fairly appreciable rewards for doing it.
Finish Megaton before you really finish it
That leads me to this next tip. Early in the game you’ll get a quest to either save Megaton or destroy it. The latter is a very fun option, but make sure you finish all you want to do there first. And then after that, why not go postal in the town to personally take everyone out before you head to Tenpenny Towers to hit the big red button? But even if you decide not to do this and want to help Megaton, make your decision and finish the quest early so that you’ll have a single place that’s yours to store all your stuff, sleep in the bed for the short-term +10% « Well Rested » experience bonus, and have your own personal butler to make you Purified Water and tell some jokes.