My approach borders on mental illness, but here goes.
For non-category purchases I use the no-annual-fee Bank of America Travel Rewards Visa (unlimited 1.5% back, plus 75% relationship bonus) for a total of 2.625%.**
We also have three of their no-AF 3/2/1 cards, where you choose the category for 3% back (+75%).
Right now that’s 5.25% back on Online Shopping, Dining and Travel, but you can change the category on each card as often as once a month. Cap for the 3% (5.25%) is $2,500/quarter per card. These also pay 2% (3.5%) back at Costco and grocery stores, however…
For groceries right now I’m getting 6% back on the Amex Blue Cash Preferred. This card has a $95 annual fee, but if you downgrade to the no-AF version and wait a couple of months, they’ll pay you $150-250 to upgrade it back. I think on my third “re-upgrade.”
Utilities and ISP charges get 5% back with the US Bank Cash+ Visa. Some of the utilities charge credit card fees, so I dramatically overpay to make the fee almost meaningless, and then just let the recurring bills gobble up the account credit.
I have several other cards that are best for other niche purchases and that meet other objectives besides cash back.
** Someone will be along shortly to point out that only an idiot would keep that kind of money at Bank of America, which is why it’s fantastic that balances in most types of accounts at Merrill also count. It doesn’t make a lot of difference to me which brokerage holds some of my Vanguard ETFs.