I like Rudy's (out of Dallas, I think; but the one I've been to is in Albuquerque); there's a place here in Phoenix (Gilbert really) called Joe's Real BBQ that I think most would consider top notch; but by far the best BBQ I've had was at a little hole in the wall in Omaha Nebraska called "Hartland BBQ". A knock-your-socks-off surprise (...Omaha???).