To someone familiar with quantum physics it becomes hard to think of something which is not quantum, because we need quantum physics to explain how atoms can be stable and why one solid material does not interpenetrate another when they are pushed against each other.
Let me expand a little on this.
Classical physics remains a wide-ranging and very important part of physics, but it does not provide the foundations. What I mean is, classical physics can say "if we have a body of such and such a mass, and so much charge, then here is how much it will push on another body, and here is the acceleration," and so on. But classical physics can't tell us what those bodies are made of. Look at the small parts of anything, and the concepts of well-defined energy and momenta described by ordinary numbers just doesn't work any more. You need the mathematics of operators and quantum amplitudes. So for me the main answer to the question "show me a quantum phenomenon" would be "how can ordinary stuff such as a table, a book, the floor, a rock, a cup, a spoon, be made of electrically charged things such as electrons and protons?" Classical physics says it would be impossible, because there is no way for a bunch of charged things to come to stable equilibrium according to classical physics. If the electrons were not moving initially then there will always be a direction to move such that they begin to accelerate. If they avoid hitting the protons by orbiting around them or by oscillating too and fro, then they will emit electromagnetic waves and rapidly (in a few nanoseconds) spiral in to the protons and the matter collapses. But this is not happening. Why not? Because quantum physics says electrons can spread out into wavy clouds and just settle around a proton without emitting energy.
Another nice example is the periodic table of the chemical elements. We see the elements laid out the way they are, because elements in each group (vertical line in the table) have similar chemical properties---they undergo similar chemical reactions. So why are there 8 main groups? And why are there 10 further groups that come in after the first three periods? And where do hydrogen and helium fit in? Quantum mechanics gives a very neat answer to all of these questions. You have states labelled by $n$, which takes integer values. Then the quantum physics of rotational energy says that for each $n$ you can have another integer $l$ taking values from $0$ to $n-1$. And the quantum physics of angular momentum says that for each $l$ you have $2l+1$ possible ways for the angular momentum direction to go. And for each state of motion of an electron there are 2 spin states. So now chemistry falls into place:
hydrogen and helium: n=1; l=0; 2 spin states so 2 possibilities all together.
Now the first period (horizontal line in the table):
n = 2, l=0 or 1, 2 spin states, makes overall (1+3)*2 = 8 possibilities says quantum theory---and that is just what is observed.
Second period is similar,
Then in the third period we have an interlude where the $l=2$ states are involved. That's a further $5 * 2 = 10$ possibilities says quantum theory---which is just what is observed.
So when you look at a periodic table of the elements, you are looking at quantum physics "written" into the chemical properties of the ordinary things around you.
But I know you still want to see something "quantum" even more directly. Have you ever heard the crackle from a Geiger counter?