I would love to take a second shot at a convex optimization course. I took one from a former PhD student of Boyd's during my junior year of college and I was not at the right point in my education for a class like that.
It touched on some really great real world optimization problems, including an interesting couple of lectures on the Netflix prize.
Indeed, best courses on SEE by quite a wide margin.
I took those via HCP (which is like SEE but for 3x the usual grad student rate) and he's a great teacher. He's not one to let his smarts get in the way of teaching, which is not true of all the professors at Stanford.