Defensive AR-15 Setup for Regular People

What do you actually need to set up a dependable, moderately-priced AR-15 for defensive use? It's probably somewhere between the bargain basement garbage guns and the tricked-out Gucci rifles for military cosplayers. Today, we're offering a few recommendations to help you pick out a reliable carbine and get it set up with a few essential accessories -- everything you need and nothing you don't.