I can't remember exactly when I first saw a Marx Brothers' movie, but I remember which one it was: A Night at the Opera. I was in either fourth or fifth grade and while I couldn't remember a single line from it, I loved what I saw. Certain scenes, like the famous Stateroom scene where fifteen people cram into one small room, made me laugh. So why has it taken me so long to get into the Marx Brothers' back catalog of films? I don't know, but after watching A Night at the Opera again, along with Monkey Business and Duck Soup thanks to Netflix, I can't get enough of their movies.
Yes, the plots are incredibly rail-thin, not all of the jokes are funny and the musical breaks are a little distracting. However, there is more to life in these films than just gags and music. A central theme of the Marx Brothers' routines is that of sticking it to uptight authority figures. I think this theme never gets old, especially when it's tarred and feathered by fast jokes and wild gags.
So much of comedy's success or failure comes with delivery. In the Marx Brothers' films, the zingers come at you fast and they rarely slow down. I love seeing Groucho quickly tear apart what someone said and then throwing it throwing it back at him or her. An exchange like, "I don't like this innuendo"/"Well, it's like I always say: Love goes out the door when money comes innuendo" hits a bullseye.
Despite the fact that a lot of their classic movies were made in the '30s, very little has aged about them. Sure, they're in black and white and the music is old school, but there is so much timeless stuff in these films that I doubt they will ever get old. What makes things even more interesting is that films like Horse Feathers, Duck Soup and A Night at the Opera came out during the Great Depression. I'm lumping together and summarizing here, but that kind of humor was greatly needed at a time like that. As a matter of fact, I can't think of a time where it wasn't needed nor do I think there will be a time where it won't be needed.