Bishop or Knight?

Most up-to-date books say the knight and bishop are both worth 3 points, but the bishop is better. In older books,it says that trading a knight for a bishop or a bishop for a knight IS a good trade.....but who is right? Well, the bishop can move farther, but the knight is more stealthy....and can do forks (see my article 'Knight Forks') and can be very useful......unlike the bishop, who, dont get me wrong, is pretty good, but cannnot weave in and out everywhere, but cna only go daigonilly