You get to pick?! We did AQA and all had to take the same two - America 1890-1945 and The Impact of Chairman Mao: China, 1946 - 1976. I found that having two very different topics was actually quite helpful in terms of revision, but really it depends on which modules your college is offering (unless they do offer all 20+ modules) and which area of history you find most interesting. I personally enjoy more modern history so these two were great for me, but a friend of mine at a different college took Totalitarian ideology and the failure of Absolutism, which was a lot more traditional.