...you can do far worse than using them to watch the BBC documentary Auschwitz: Inside the Nazi State on Netflix. I just finished it, and it's pretty devastating.
The series obviously features a lot of interviews with survivors, but they also spoke to a number of perpetrators. If you want an example of the banality of evil, watch a guy who worked at a desk at Auschwitz talk about hiding the stuff he stole from inmates so he wouldn't get caught for corruption, then respond to a question about whether or not he felt guilty about lining his pockets while the people in the camp died by saying, and I quote, "Absolutely not. Everybody is looking out for themselves. So many people died in the war, not only Jews. So many things happened....If I thought about all of that I wouldn't be able to live one minute longer."
The series also features some very striking music, including this piece—Arvo Part's "Spiegel im Spiegel"—which I'd seen in several movies before and always found really beautiful and evocative, but in the context of this documentary, it just rips your guts out: