I have great genetics... when it comes to teeth anyway.
My wife is always hoping I'll come out of the dentist office saying that I have a cavity... but I never do. Besides my wisdom teeth being removed in my mid to late teens I can't remember any other troubles since I was about eight years old.
I only brush once a day. Only floss occasionally. And my teeth are clean enough/white enough (besides the dead one, skateboarding accident as a kid) that I don't use any whitener other than special toothpaste.