You just need to have the basics!
The Generic Enemy
Basically, a goomba. No attacks besides walking into you.
The Generic Flying Enemy
The flying goomba. Still mostly harmless.
The Spiky Enemy
The exception to the 'kill with jump' rule. Generally an annoyance, as it is invincible by normal means.
The Useful Enemy
It bounces you up, or it leaves behind a shell to attack with... whatever it does, it's useful. Maybe more than one variation, and maybe more than one Useful Enemy type.
The Trap Enemy
It tries to crush you, like a Thwomp. Should probably look like one too, for maximum cliche.
The Obstacle Enemy
More an invincible obstacle than any sort of enemy, but it is anthropomorphic, so it is counted as an enemy.
The Annoying Enemy
It can home in after you, be functionally invincible, or be placed in frustrating places. But it is definitely annoying.