Stan Laurel and Oliver Hardy, of course. A few years ago here, I highly recommended a ten-DVD set containing most (not all) of the talkies they made for the Hal Roach Studio between 1929 and 1940. It's not complete but it's full of great stuff and most of the video is of high quality, plus there are some wonderful special features. For example, it includes the "foreign" versions they made of some of their movies.
So why am I plugging it again? Because Amazon has slashed the price on it. It was around a hundred bucks and it was a bargain at that price. For a limited time — note that term: limited time — it's $42.49. Here's a link to order it and if I were you, I wouldn't delay. I've played the heck out of my copy.