re: Which Credit Card should I pick?

I always have a 2 card system, 1 amex and 1 visa/mastercard.

Amex usually has the best all around rewards, but is not accepted at some places, so a backup is necessary.

Check out the Amex Blue preferred if you spend a lot on gas/groceries.

I travel pretty often and don't spend much on gas, so I have the HHonors amex, but if hotel/airline points isn't your cup of tea, this is the usually best cash back card.

For a visa, the Citi Forward is a great pair, as it offers a unique set of high rewards 4.2% back on amazon and restaurants).

With this combo, you will be getting

6% cash back on groceries
4.2% points back* on restaurants
4.2% points back* on Amazon
3% cash back on gas
1% cash back on everything else

*you get 5 points per dollar, but to buy a $50 gift card requires 600 points. It is possible to get the full 5% back, but it requires you to use the points for direct shopping.