Game Changer is incredible, especially the episodes where Sam tortures Brennan (essentially all of them that feature Brennan).
I've also seen a fair bit of Make Some Noise. I find it to be more hit or miss than Game Changer. It's never bad but it's not usually quite as much unbridled chaos as Game Changer.
I've been slowly making my way through the D20 content, I watched all the seasons of Fantasy High, and I'm almost done with Unsleeping City. I definitely liked Fantasy High more, but Unsleeping City is great. I'm undecided which campaign I'm going to watch next, but I'm open to suggestions!
D20 on a Bus is amazing. Katie messing with a bunch of experienced DMs is hilarious, and watching Brennan get increasingly exasperated is always entertaining!