Super Macho Man is where the difference between Punch-Out!! and Super Punch-Out!! is most pronounced. Mr. Sandman is easy compared to this guy.
First, leading with your left is dangerous. He will usually duck and uppercut before you can dodge. For the same reason you don't want to keep throwing left jabs when you have him stunned until he blocks, because he won't block... he'll duck and hammer you. Try to remember how many jabs you can get in whenever you stun him in a particular situation.
Super Macho Man has two spin punches: the Spin Punch and the Super Spin Punch. The Super Spin Punch knocks you down instantly, and the normal Spin Punch still hits pretty hard. You can tell when he's about to do the Super Spin Punch because he jumps over to your right before doing it. Whenever he jumps over to the right, he's about to do this move. You must duck (not dodge) the punch. He often does this after a jab, so do not develop a habit of dodging immediately after countering his jab, thinking he will do a hook or uppercut. If you dodge prematurely and he starts the spin punch instead, you will get hit. When he does the Super Spin Punch he will always do two spins. Duck both, then give him a right and three lefts.
He does not jump over to your right before doing the normal Spin Punch. He will very quickly do something that resembles a quick dancing movement, sort of wobbly, then he will wind up. He will usually spin multiple times and there is no telling how many he will do until he stops. There is a pause between between the individual spins and you can hit him between them.