Here is an entire undergraduate course in abstract algebra, taught by retired Harvard professor Benedict Gross.
http://matterhorn.dce.harvard.edu/engage/ui/index.html#/1999...
I know Gross personally, and have heard him lecture several times; although I haven't watched these lectures in particular, I'm guessing that that they're just about as good as it gets.
You can also find online lecture courses in a variety of subjects offered by MIT, Yale, etc. It's telling that these universities feel confident in giving away this material, to anyone, for free.