I don't keep up with all the latest gee-whiz toys in the black gun world but I know some of you do. So please use some of your knowledge to help me get a rifle put together.

What I'm looking for is a 5.56mm, AR platform rifle that would be on hand in case things got really bad (riots, natural disasters, etc.). It would be the main defense weapon in a suburban setting. Tell me what rifle, sighting system(s), and useful add-ons that would combine to fill the need. Cost is not an issue but reliability, shoot-ability, toughness and reliability (again) are paramount.

Thanks, RS