Chaos theory is about the sensitivity of the outcome of a
deterministic process to the starting conditions. It is QM alone that suggests that nature is not deterministic, not chaos theory.
Chaos makes prediction of a chaotic system difficult, in that you have to know the starting conditions with certainty. Even if our universe was deterministic, establishing starting conditions exactly is nigh on impossible, as we have limits to our technical ability to measure precisely (we generally work to within margins of error). QM, however, introduces
inherent uncertainty, thus making predictability of such an indeterministic chaotic system impossible.
As Seattle says, weather is the obvious example, and it was the efforts to model the weather that led, I believe, to the butterfly comment... a
very slight change in the numbers input into the model resulted in the forecast indicating a tornado would end up somewhere else than originally modelled.
Orbital mechanics can be chaotic - especially three-body problems.
Then there's double or triple pendulums... look it up on youtube.
Whether our lives are a demonstration of chaos is possibly up for debate. To be sure we would need to be able to reset the "system" and introduce a minor change, and see what unfolds. Unfortunately we can't reset. It may be that we have a tendency to dampen toward a certain position. But then there are very small events that would have significant changes: picking just the right 6 numbers in the lottery, for example, rather than only 5.

Humanity as a whole might be rather unchaotic, though, more likely to have dampening effects when treated as a whole.
Asimov wrote his Foundation series on this notion, that humanity's path is ultimately predictable (and thus unchaotic). Hari Seldon's Psychohistory etc. Entirely fictional, though.
