I really just cant decide between an english mastiff and great dane?

I initially was going for an english mastiff but started doing a little research on Danes and then ended up doing alot of research on both breeds and I am in love! With Both! I need help deciding which dog would be a better fit for me. I am a single 20 yr old woman that lives alone. I have lots of experience with dogs but this will be my first giant breed. I do live in a medium sized apartment but have time to adequately exercise them twice a day for as long as I need to. And lots of training and socializing of course! Please help me decide because these are both such great dogs and if I could I would get one of each but thats not an option right now. Just one :)