Baseball is darn near a perfect game as it stands, but I would like a pitch clock put in place. There's no reason a game should last four hours. That's the beauty of college basketball in my opinion. You know if you sit down to watch you'll be done in about two hours with tv timeouts and everything.
I've seen very few baseball games last 4 hours. Unless Edwin Jackson is pitching for the Cubs because he can't get anyone out, but I digress.