Fairly off-topic, but for me the best "lessons" (or at least, the best free lectures online) are Ronen Har-Zvi's on the St. Louis Chess Club's YouTube page.  Sitting down here in the 2200-2300 range, I find most of his commentary spot on and insightful.  He seems to identify the critical moments in games extremely well and cut through the thickets of variations, honing in on important details.   

There are so many free resources out there for chess instruction these days, I'd encourage people to look at them.  In my opinion, most online lessons are not targeted to the student, just mass-produced stuff.  So it'd be better to find a local teacher to go over your own games with who can provide you with personalized feedback, and then find the best free lectures on the web to learn from.  At least that's MHO.

I have seen all...Most of them are the best lessons seen