We looked at the best cash-back credit cards for use at the pump a few days ago. Now it's time to check out the best cards for the rest of our purchases: wireless accounts, drugstores, restaurants, office supplies, groceries, and more. With prices on just about everything rising at a steady pace, we all need as many discounts as we can get!

How Cash Back Credit Cards Work

So, the way these cards work is that you use them to spend at various merchants and they either: 1.) credit you a percentage of purchase and take that off of your next statement automatically (American Express) or 2.) convert that amount into points, which you can redeem for a cash-back check or other goods. Either way, you get a certain percentage back on every purchase, it's just that the former way is more hassle-free.

Why Use Cash Back Credit Cards?

Because it's free money. Just take a couple of minutes to apply for them and when you get it throw it into your wallet. When you have a certain transaction, just make sure to use the corresponding credit card. You should be able to get by on all your purchases with the four credit cards listed below. To make it even easier, write on the back of the card what to use it for in permanent marker.

"It's too much of a pain."

To those of you that say it's too much trouble to remember to use and pay off each one every month, well, I guess you just don't care about free money. Go ahead and keep using cash or your regular card and get nothing back. I'll gladly accept some of the credit card corporation's money.

The best credit card to use for gas purchases:

 5%) The PFCU Platinum Cash Rewards Visa

 Covered in detail in the post Cash Back on Gas Credit Cards, this card will give you 5% back on all purchases at the pump. There's no annual fee and the rewards are credited to your account every month automatically. No restrictions on rewards. The only downside is that you must be a member of the National Military Family Association—easily done with just a one-time $20 tax-deductible membership fee. Definitely worth it with gas prcies as high as they are now—that's $.20/gallon back! (With gas at $4.00/gallon.)

The best credit card to use for grocery purchases:

3.75%) Chase Freedom℠ Visa (Update 12/01/2008: Terms Have Changed)

There used to be many cards that would offer you 5% back at supermarkets. Now all of those cards have either a.) stopped accepting new applications, or b.) have imposed a three-to-twelve month time limit on the rewards, after which they revert to something like 1-2% back. You could grab a new card every year in order to get the most back from your grocery purchases, but to keep it simple I'm advocating sticking with the Chase Freedom™ Visa. It gives you up to 3.75% (when you wait to redeem at the $200 rewards level you get an extra $50 back) back on your top three (five with linked Chase checking account) spending categories, groceries included. More info can be found at this post: Chase Freedom℠ Card: 3%+ Back On Anything.

The best credit card to use for office expenses:

5%) American Express SimplyCash Business Card

This card will give you 5% back, automatically credit to your account, on all office supply purchases. This includes stores like Office Depot, Officemax, Staples, etc. Which, of course, includes big budget things like furniture, computers, etc. It's a business card, but you don't have to be a business to apply. Just use your name as the business name.

The best credit card to use for your mobile/cell phone bill:

5%) American Express SimplyCash Business Card

Same as above, you get credited 5% back for all of your monthly mobile phone expenses. Have an iPhone with a full data plan? Well, if you're spending around $200/month then that's $10 back on every statement.Also great for those of you with a mobile internet card/data plan for your laptop.

The best credit card to use at drugstores:

3.75%)  Chase Freedom℠ Visa (Update 12/01/2008: Terms Have Changed)

Just like the grocery store issue, there used to be many cards that offered 5% back at drugstores…but they're all gone now. Use the Chase Freedom™ Visa for 3.75%, still better than what you'll get with any other card out there. More info here: Chase Freedom℠ Card: 3%+ Back On Anything.

The best credit card to use at restaurants:

3%) Citibank Professional Cash MasterCard

This card will give you 3% back on all restaurant purchases, as opposed to the Chase Freedom™ Visa's restriction to just fast-food restaurants. As a bonus, you also get 3% back on gas, office supplies, and car rentals (pretty much equivalent to the Chase Freedom™ Visa card).

The best credit card to use for every other purchase:

3.75%) Chase Freedom℠ Visa (Update 12/01/2008: Terms Have Changed)

I've recommended it before, and I'll do it again here. There is no better all-around card for everyday expenses than the Chase Freedom™ Visa card. 3-3.75% cash back on three-to-five top spending categories automatically on one card. That's why it's the credit card that I use the most. More info here: Chase Freedom℠ Card: 3%+ Back On Anything.

Alright, that's it! Did I miss anything? See any errors? Let me know by commenting. Thanks!