The Marriott Rewards Platinum Premier card by Chase. You get 5 pts per dollar for Marriott spending and 2 pts per dollar for flights and car rentals, 1 for everything else. Also, there are numerous promotions throughout the year that require you to use this or the regular Chase Marriott Rewards card (for the small difference in annual fee go for the premier card -- the regular one only gives you 3 pts per dollar spent at Marriotts). ProfChiara
You will also get a premier visa annual free night valid for all Marriott hotels (category 1-5) which basically more then covers the annual cost of the credit card. There are also promotions through out the year, such as offering 10,000 points if you spend $9,000 over 3 months period.