If I recall correctly the Discover 2% is not a true 2%, you are tiered. Starts below 2%, eventually reaches 2% for (lets say) the purchases between $5k to $15k, then falls to 1% or 0.5% for additional purchases.
I'm not certain if this is still available, but my Capital One Small Business Rewards has no annual fee and provides 2% "cash back". I receive 2 points per dollar spent on all purchases. If you purchase travel related items (air, car, hotel, parking, timeshare maintenance, etc) you can later request a credit on your statement by redeeming 100 points per dollar you want credit for. So I buy $12,500 of product and get 25,000 points which I can then use to get $250 statement credit on a $250 travel item.
You can redeem points for other items, but non travel credits and cash back work out to a 1% redemption.
One card I liked a lot was the Citi Premier Pass Card Elite which was $75/yr. I got 1pt per $ spent + 1 bonus pt/$ for supermarket, drugstore, gas, communter trans, parking and also 1pt per mile flown for all tickets bought. If you fly a lot, this is the card for you. My favorite purchase went as so:
- Buy a $500 ticket LAX-OGG R/T. Get 500 pts for the purchase and 5,400 pts for the miles flown. the card is not related to the airline I fly on so I also get the 5,400 Airline Miles. Thus, a $500 purchase yields 5,900 pts, if I made this flight 5 times I'll have spent $2,500 for 29,500 pts, 25,000 pts gets me a 48 state domestic ticket worth $250-$500 (let's say $375) so $375 / $2,500 = 15%!
OK, the $75/yr cuts into the 15% and you will not always get 5,900 points on a $500 ticket. But if you charge everyone's tickets to your card (it doesn't matter if you fly or not) and / or you fly frequently, the $75/yr becomes a very small deterent and even on shorter routes you'll be getting 6-10% on the amount of your purchase.
The points you accumulate are added to your Thank You Rewards account (setup when you get this card, or you might alraedy have one) and you have 5 yrs to use the points. In my experience it is best to use the points for air tickets where you still accumulate air miles with your airline! The redemption is fairly standard at 100 pts per $ spent on a ticket with a few cases where highly booked flights might cost more points.
I was even able to (with a bit of perseverence) get the call center to book specific fare classes so I could later use upgrade vouchers to upgrade into First Class. Sometimes those tickets required a little more points as well, but not always.