Most under utilized is the jab. Most important punch you can throw and it's so much more deadly in MMA with the tiny gloves. We've seen guys get dropped and even KO'd by jabs, and they can cause so much superficial damage like swelling and cuts.
And it sets everything up. Werdum hardly missed a straight right against the taller Browne because he hid the straight behind a jab or double jab.
Jabs are lethal.