I generally prefer the less speculative aspects of quantum mechanics. For instance, how it is that so much of chemistry can be "explained" by quantum mechanics, or how electron tunneling can occur in proteins and play such an important part in the production of ATP in pretty much all of life.

I liked Sussikind's lectures:

http://www.youtube.com/watch?v=0Eeuqh9QfNI

The mathematics he uses in the course is minimal, but I feel like he addresses what the main changes in intuition about the natural world that quantum theory would suggest.

To me, the main difference between "classical" and quantum theories is in our ways of knowing and not knowing things about the world...the difference between "classical" measurement and information, and quantum measurement and information.

In "classical" theories:

1) We have observable variables that can be measured to pretty much arbitrary precision and accuracy.

2) We can, in theory, measure these observable variables together to arbitrary precision if we can do it very carefully.

3) Uncertainty is just "not knowing", and can be explained using basic probability theory.

In quantum theories:

1) We have observable "operators" that can result only in "proper" (eigen) values when measured.

2) We can only measure "commuting" observables together to arbitrary precision. It is not possible to measure "non-commuting" observables together to arbitrary precision, no matter how careful we are.

3) Uncertainty can be fundamental to what we are measuring. There are many philosophical interpretations of why this is the case. But a naive interpretation of just "not knowing" because we aren't careful enough is no longer tenable.

Also, I don't think we need to go into idle speculation to have an interesting discussion about quantum mechanics.

For instance:

1) Why do we find it difficult to compress things in condensed states? (for instance, why do people call water "uncompressible", but in nuetron stars, matter can get compressed beyond this.)

2) Why does the periodic table take the form it does?

3) How does light interact with matter?

4) Why do we get the results we get from the double slit experiment?