Since american express cards are not always accepted, I would also look into the Chase Freedom card that earns 5% on rotating categories and 1% on all other purchases. I use it for the rotating categories.
Additionally, I have an Amazon.com credit card that gets 3% at Amazon, 2% on restaurants, and 1% on everything else and an American Express Costco card that gets 3% on gasoline, 2% of restaurants and travel, and 1% on everything else.
The American Express costco card only redeems the rewards once annually, and it's a check that has to be cashed at costco (or used at costco), so I tend to avoid using this card unless I have to. I have to use it at costco for purchases unless I want to use cash or debit. The Amazon and Chase 5% cards allow me to redeem rewards monthly when the balance has exceeded $20.
I was not aware fo the Fidelity card, and do not have any investments at Fidelity. But it gives you 2% that is invested at fidelity in $50 increments. Sounds interesting, I will have to decide if its worth having a fidelity account or not.