Dr. Susskind of Stanford has been continuing work on his course series ‘The Theoretical Minimum’. He’s even set up a full website for it which you can find here:
You’ll find courses on Classical Mechanics, Quantum Mechanics, Special Relativity and Electrodynamics, General Relativity, Cosmology, Statistical Mechanics, Quantum Entanglement, Particle Physics (3 courses), and String Theory.
He describes the aim for the courses on the front page,
“A number of years ago I became aware of the large number of physics enthusiasts out there who have no venue to learn modern physics and cosmology. Fat advanced textbooks are not suitable to people who have no teacher to ask questions of, and the popular literature does not go deeply enough to satisfy these curious people. So I started a series of courses on modern physics at Stanford University where I am a professor of physics. The courses are specifically aimed at people who know, or once knew, a bit of algebra and calculus, but are more or less beginners.”
If you’re interested in learning some deep physics, you should check it out!