Ok, so this really caught my attention; what a fantastic idea!
Then I got thinking. I'm procrastinating from planning for my day job, and this is awesome enough to keep me busy.
I'd want most of my printoffs to be for general gain, rather than personal gain, but I'm not sure that's too possible; I'd get enough money together to build a secure bunker in every country in the world, hidden deep within the mountains and well-provisioned. If the news that I had such a fantastic device ever got out, unscrupulous people would want it, and I'd need a way to throw them off the scent. Each bunker would be equipped with a teleporter linking it to any of the other bunkers, meaning that I can switch on a regular basis without them ever knowing where I was.
Now, things to make; oil wouldn't help much, I think, as eventually we're going to need a pollution-free option. The zero-point energy gun from Half Life 2 will do nicely, as it can power the world for absolutely free; I'd definitely spread the idea that each country has one in it, but in actual fact the one powering things will be on the moon.
Although the bunkers will be there to contain the printer when I actually use it, I'll need somewhere to relax and be normal. The trick will be to slowly increase my wealth and personal status without attracting undue attention. Alternatively, I could just 'win the lottery'. Once I own a tropical island somewhere I'd make sure it's uncharted and then get to work with a mansion, Persocom servants, that sort of thing; the real centre of operations will be an underwater base from just about any game ever. I've always liked the idea of the teleport gun from Unreal Tournament for getting around; I'd probably have the training sections of Lara Croft's mansion for working out in.
Hmm, what else? Ending world hunger would be kind of hard, and looking back, these are mostly personal gain. A Death Note, possibly, to end crime. But there'd be none of the pussy-footing around from Death Note; I'd be straight in there taking out world leaders.