An interesting pairing of mins, indeed. The Heroclitean fragments were more philosophical and oblique, whereas Diogenes' words came across as (often amusing) aphorisms. Some of my favorites from each:
Knowledge is not intelligence.
History is a child building a sand-castle by the sea, and that child is the whole majesty of man's power in the world
If every man had exactly what he wanted, he would be no better than he is now.
Bigotry is the disease of the religious.
Sea water is both fresh and foul: excellent for fish, poison to men.
Having cut, burned, and poisoned the sick, the doctor then submits his bill.
Of what use is a philosopher who doesn't hurt anyone's feelings?
Plato winces when I track dust across his rugs: he knows that I'm walking on his vanity.
When I die, throw me to the wolves. I'm used to it.
Everything is of one substance. It is custom, not reason, that sets the temple apart from the house, mutton from human flesh for the table, bread from vegetable, vegetable from meat.
One wrong will not balance another: to be honorable and just is our only defense against men without honor or justice.
In the rich man's house there is no place to spit but in his face.
I pissed on the man who called me a dog. Why was he so surprised?
I've seen Plato's cups and table, but not his cupness and tableness.