2 days trip in Istanbul

Hi dear InterNations fellows....

I'm currently liveing in China, however I should have a short stop in Instambul on my way back to Brazil for a home leave....

Would you be so kind for suggesting which are the top 5 attraction in Instambul that I can't miss?! Any tip about how to enjoy better those places? Any danger or annoycance to aware?

Thanks in advance!!!!!!
Rafhael