re: What psi pressure washer do I need?

I have an old 2,000 PSI that does fine for all of that. The only pain I have with it is the sidewalk and driveway. I probably need a new attachment or tip for it, but I just don't bother with the driveway anymore. The sidewalk, deck, brick, and other uses, it is fine for. I did have my driveway pressure washed by the crew that painted my house a few years ago. They pressure washed the entire house (well, the brick part) after they were done to get rid of any drippings from their painting, and then the driveway. I've never seen concrete so white, but they had some massive washer on big wheels and one of those big round head that rolled around on the ground. So if you're going to be doing driveways, get something like that. Otherwise, just the basic one with an adjustable tip is fine.