The best cash-back credit card?

What's the best cash-back credit card out there? I've pared it down to 4 choices:

• The American Express Blue Cash card, where you can earn up to 5% cash back


• Citibank's Dividend Platinum Select Mastercard, where you earn 2% cash back


• Citibank's Professional Cash Mastercard, where you earn 3% cash back


• BP Visa, which pays 5% on gas purchased at BP/Amoco stations

Before I get started, please know that if you can't pay your credit card balance in full every month, your best option is to NOT use it. It's really that simple. I'll add a subsequent post that will discuss how to prioritize which bills to pay first.

The fine print:

• With the American Express Blue Cash, you can earn up to 5% cash back for "Everyday Purchases" at supermarkets, gas stations and drug stores, but only once you hit their 2nd tier. "Everyday Purchases" specifically excludes purchases made in departments of superstores or warehouse clubs.
  
  The first $6500 you charge of "Everyday Purchases" only earns 1% cash back. All other purchases earn 0.5%. Once you break the $6500 barrier, you'll earn 5% on "Everyday Purchases" and 1.5% on everything else. Not bad . . .they even offer a calculator to help you figure out what your cash rebate would be.



• The Citi Dividend Platinum Select Mastercard pays 2% cash back on purchases made at supermarkets, drugstores, gas stations, convenience stores, and utilities including cable. (Don't get too excited about the utilities thing. All utility companies charge a processing fee ranging from $1-$3 for paying your bill with a credit card. The process isn't automated, so you'd have to phone in each time your bill was due.)
  
  Purchases netting 1% cash back include purchases made at warehouse clubs, discount stores, department stores, and online/catalog purchases (unless the merchants appropriately identify the transactions).
  
  Rebates are capped at $300 per calendar year. Read the fine print here.
  
  I've had this card for a long time and it's worked out well, but due to the card's limits, I think I'm leaving some money on the table.



• 
  The Citi Professional Cash Mastercard looks good at first glance, paying 3%, but that 3% is offered on a different group of purchase categories. You get 3% on purchases made at gas stations, restaurants, certain office supply merchants and auto rentals.
  
  This time, warehouse clubs, discount stores, department stores and convenience stores are excluded from the 3% tier and earn the default 1% rate. Rebates are capped at $500 per calendar year. Read the fine print here. When you're ready to apply, do a Google search and you might be able to find out how to get a $100 to $150 sign-up bonus.



• 
  The BP Visa earn 5% rebates at all BP locations, 2% rebates on eligible travel (Airline, Auto Rental, or Lodging) and dining (non-fast food) purchases and 1% rebates on all other eligible purchases. Gas at non-BP stations are not eligible purchases.

I've crunched the numbers and I think the best option for us is going to be a combination of the American Express Blue Cash card and the Citi Professional Mastercard. We'll use the American Express Blue Cash card for all purchases besides restaurants, gas purchases and wherever the American Express card isn't accepted.

Getting 3% back on restaurant and gas purchases is a nice benefit of the Citi Professional card. I suppose we could earn 5% on BP gas by adding the BP Visa to the mix, but that's just too much of a headache. I really don't want to carry around 3 cards!

The American Express card really pays once you spend above the $6500 level, which we tend to get to fairly quickly every year. We'll give this a shot for 2007 and if it doesn't work, a back-up plan would be to use the Citi Professional card only.

Does anyone else have any other bright ideas? Feel free to comment . . .