I find that showing up at the door naked works pretty well. They see me and they turn and walk right away. When I had a house, I used to turn on my sprinkler system when they'd get near my lawn. I'd set the sprinkers so they'd get soaked walking anywhere near my house. Whenever any religious group or proselytizer gives me literature or one of their books, I say "Hey, thanks for the free toilet paper, you can never have too much." I don't blame you for bitching about these people coming to your door, I get one at least every week in my apartment complex and I have repeatedly told the management, "If these people show up at my door and bug the shit out of me, I don't want any flack from you guys about me showing up at my door naked with a gun in my hand because these people are trespassing and you know it." Well sorry to hear that they keep bothering you and hopefully these tips will work for you.
A simple "No thanks" and keep walking works.
When they arrive at your door step, say the same thing and shut your door.
Put a polite sign on your door about no solicitors, flyers, or religous information.
If I didn't like things where I lived, I would work to change them or I would sell my home and move. O and before I made the move I would look at the local laws in my new city of choice. You see in my city it is against the law for those without a city permit to go door to door soliciting anything so it's only maybe once every two years when there is any unwanted ring of my bell. I guess they don't issue very many permits. :)