Active Sam's Club members who fill up at Sam's Club fuel centers regularly — 5% cash back on fuel at Sam's Club stations (up to $5,000/yr, then 1%), plus 3% on a broad dining and travel category, with no card-level annual fee. Accepted anywhere Mastercard is.
Frequent PayPal checkout users who want 3% back routed through PayPal specifically, plus a flat 1.5% everywhere else, with no annual fee and no category tracking.