I finished re-reading "Mother Night" yesterday evening. I've always liked this book... it's about a man who is an undercover American spy in Nazi Germany whose cover involved being a Nazi propagandist. The action of the novel takes place as he retells his story while being tried in Israel as a Nazi war criminal, because the USA refuses to acknowledge that he was their agent. And, of course, it's a comedy.
This is a great book... an amazing example of how to explore serious issues (Do the ends justify the means? Do we become what we pretend to be? Can we commit unforgivable crimes against ourselves?) in an entertaining, often hilarious way. Let's be honest, it's hard to write a comedic novel about the Nazis. But here it is. It's a great read and worth your time if you've never read it.