Many credit cards offer you cashback on your purchases. Almost all cashback cards now offer you at least 1% cashback on all your purchases, only a few offers as much as 5%. The catch is that the categories rotate every quarter and you have to opt in online. Below are the 5% rotating categories for the first quarter of 2016.
Earn 5% cash back on up to $1,500 in combined purchases at Gas Stations and Local Commuter Transportation* (including taxis, subways, local commuter buses, and trains; not including parking, tolls, and Amtrak® purchases) from January 1 - March 31, 2016. See FAQs for more information.
Earn 5% cash back on eligible purchases at The Home Depot® and home furnishing stores between January 1, 2016, and March 31, 2016. The offer becomes active within 2 business days of when you enroll in this offer, or January 1, 2016, whichever is later. Note that there is no quarterly benefit limit but your cashback is limited to $300 per year. See this link for details and the cashback calendar for the remainder of 2016.
Earn 5% Cashback Bonus on up to $1,500 in purchases at Gas Stations (stand-alone) and for Ground Transportation from 1/1/16 (or the date on which you sign up, whichever is later) through 3/31/16. Purchases made at Gas Stations affiliated with superstores, supermarkets and warehouse clubs may not be eligible. Ground Transportation purchases made through travel agencies or travel aggregator sites will not be eligible. Purchases made using tap-and-pay, mobile or wireless card readers, virtual wallets or similar technology may not be eligible. See Cashback Bonus Program Terms and Conditions for more information.
For purchases falling outside these rotating 5% cashback categories...
My go-to cashback credit card is the CITI DOUBLECASH card. Unlimited 2% cashback on all purchases - 1% when you buy and 1% when you pay your bill. No annual fee. No watching the calendar. No category tracking. No headaches. You can learn more about it here.