What credit card for major purchases? Cashback, warranties, etc

Thought I would pipe in. I have a Blue Cash card from American Express. I think it's a grandfathered in card, so it's better than the Costco one and isn't offered anymore. I get 5% on gas & groceries and 2% on everything else. The Costco one is good though.

I have used the extended warranty 3 times, and the 90 warranty once over the last 5 or 6 years. I've had the card since 2003.

90 warranty was a full refund of $269
First 1 year warranty was for $259
Second 1 year warranty was for $449
Third 1 year warranty was for $165, they did a repair - this item cost $699 originally, so it the price of the item may make a difference.

I've never had a problem with my Amex. When I have, they quickly fixed it. My favorite card by far, and I get about $700 back from them in their cash rewards each year.

Edit:

To clarify, I've never had a problem with American Express. I did have an issue with a vendor putting charges on my account whom I had never dealt with. Multiple charges over several months on different card numbers. Ultimately, the person I ended up speaking with in American Expresses fraud department said that she suspected someone inside of American Express since they were using my replacement card numbers as they were issued. She said it would be taken care of and I never had another charge from the company I had issues with again.