I've spent a ton of time dealing with personal finance, and have made plenty of great (and the occasional not-so-great) choices when deciding on credit cards, accounts, and more. Here are some of my recommendations. My recommendations do all have special links so if you sign up for any credit card, I'll earn a (slight) commission. Don't worry, I have a day job and will only recommend cards that I either personally own or have owned, along with what's bad about the card (if anything).
Amazon's main credit card is through Chase, and I've had this card ever since it came out. With thousands of dollars spent on Amazon annually alone, I've earned more cashback on this card than any other credit card I've ever owned combined. That's not just because of how much time and I spend on Amazon, it's because of the excellent 5% cashback on all purchases. It's cheaper to buy a Macbook from Amazon than Apple, or really anything except when the price difference between another retailer is that much lower. There's no downside to owning this card; even if you only shop at Amazon occasionally, there's no cards that have the same return for shopping at Amazon (and Whole Foods).