I say this quite often, but there is a lot of untalented people and just plain garbage and filth on YouTube (which is to be expected since it's a public forum). But every now and again, you luck upon some true talent.
Stevie Wonder was out to dinner in Brazil when he heard a street musician playing sax outside. Stevie grabbed his harmonica and went out and jammed with the guy. A chance encounter the sax player will always remember, I'm sure.