What hotel to choose in centre of Istanbul?

Is there anyone who could help me choose a good hotel in the centre of Istanbul? I should go there in two weeks, and it’s not that I have too much time to find a place to stay. Especially, since I have never been there before, and have no idea which hotels are better and where I won’t spend too much money for the accommodation. Any suggestion will be helpful.

If you can afford staying in a five star hotel, then the Divan Hotel is the best choice for you. If not, then I can assure you that if you choose The Ramada Hotel and make sure to ask and get the superior room, you won’t regret. But let me give you a valuable piece of advice. Wherever you decide to stay, in this hotel or another one, be sure not to leave your expensive and valuable things in the room, because if they disappear (which is not so uncommon), you probably won’t see it again.