So _Last Week Tonight_ does longer-form, more in-depth comedy reporting? That actually seems like a terrific mix, and definitely a hole in the market. People want to be entertained and informed, and while _Colbert_ / _Daily Show_ provide good breadth, we need good depth as well.
I've watched a good number on YouTube. They are generally longer-form, and get into some more detail. I find them quite enjoyable, but I think you may be disappointed if you go in expecting a lot more depth. I don't think you want your sister telling you that's how she keeps in touch with American news (hypothetically speaking :)