If you pay your balance every month, you should be getting more than monthly bills from your credit cards.

You should be earning miles or points toward airline tickets, gift cards, electronic gadgets or even cash rebates.

Just look at how one consumer, Sabrina Karl, took control of her credit cards and made them work for her.

That's why we checked out dozens of cards to find the best rewards cards for you. We put them into three categories: air miles, cash back on gasoline purchases and just plain cash back.

Most of our picks charge no annual fees. Some bestow extra miles, points or rebates on things you buy the most -- groceries, gas and pharmaceuticals. They also make it quick and easy to get a check or redeem the miles and points you've earned.

Interest rates weren't a big concern -- in fact, some of them are a little high.

But rewards cards make the most sense for consumers who pay their balances off every month. If you don't, you need a card with the lowest possible interest rate.

That said, here are our choices for the best reward cards:

Airline miles

None of the individual airline cards makes the cut. As soaring fuel prices force carriers to offer fewer flights and reduce the number of seats available to frequent fliers, it will be harder than ever to redeem the miles in those programs.

And from everything we've heard, it's pretty tough already. There are more miles needed for most flights and extra charges.

That's why we think the Capital One No Hassle Miles Rewards is your best bet.

It allows you to earn a hefty 1.25 miles for every dollar spent. Those miles can be redeemed on any airline, with no blackout dates, no limit to the number of miles you can accumulate and no expiration date as long as you keep using the card. And there is no annual fee.

For tickets costing:

• $150 or less, you're charged 15,000 miles.
• $150 to $350, you're charged 35,000 miles.
• $350 to $600, you're charged 60,000 miles.
• More than $600, and you're charged 100 times the price in miles. So, if your ticket is $750 that would cost you 75,000 miles. There is no limit as to how many miles you can spend or how expensive the ticket can be.

The reward system is flexible too, allowing you to redeem miles for merchandise, charitable donations, gift certificates or cash rebates.

The only drawback is that you need excellent credit to qualify.

If your credit is good but not quite good enough to land a No Hassle Miles card, consider the Miles by Discover Card.

You can travel on any airline with no blackout restrictions and get double miles for up to $3,000 in travel and restaurant purchases each year. Otherwise, you earn one mile for every dollar you charge.

In addition, you can earn 1,000 bonus miles each month you make a purchase during the first 12 months you have your card (12,000-mile cap). You also can use your miles for hotel stays, car rentals, cruises and other travel-related rewards.

If you don't use your miles, you can get gift cards to use for purchases at 50 brand-name partners' online stores or you can redeem them for cash.

Gas rewards cards

If you put in a lot of time behind the wheel and spend really big bucks on gas every month, a little cash back might lessen the sting. We have two suggestions:

The Capital One No Hassle Points Rewards Credit Card offers more points than any other card we've seen. You get five points for every dollar you spend on gas, groceries or at pharmacies, and one point for every dollar spent on other items. And there is no cap on the number of points you can earn.

Once you've earned 700 points, you can begin redeeming them for merchandise, gift cards or good old-fashioned cash.

This card has its drawbacks. There is a $29 annual fee, but earning five points instead of two or three would make it worthwhile if you're serious about accumulating points. The APR is also a very high, with a variable rate of 16.65%. But as we said, if you are not paying off your balance every month, you probably shouldn't have a rewards card.

The Chase PerfectCard allows you to earn rebates on all of your gas purchases. You get a 6% rebate for every dollar spent during the first 90 days you have your card and a 3% rebate after that. There is, however, a $500 per month cap on how much you can earn at this level. You also earn a 1% rebate on an unlimited amount of purchases for anything other than gas.

There is no annual fee and you only need good -- not excellent -- credit to qualify.

Gift and rebate cards

If you're looking for a card with generous options for earning and spending your points, you can't do much better than the Citi Diamond Preferred Rewards Card.

There's no annual fee and you only need good credit to qualify.

You get a $50 gift card (worth 6,000 points) if you charge $100 in purchases within three months after receiving your card, or you can save those points and combine them with additional points for more expensive rewards.

Cardholders earn five points for every dollar spent at supermarkets, drugstores and gas stations for the first 12 months and one point for every dollar spent for all your other purchases.

You can redeem points for travel, a variety of products including electronics, sporting goods and so forth, as well as for restaurants, gas and gift cards at a wide variety of name-brand merchants. Check out the rewards at Citi's Thank You Network.

Have we saved the best for last? Maybe.

For many consumers, cash is the best reward.

The Chase Freedom Visa card provides 3% cash rebates on everything you spend. You get cash back for every eligible $1 spent at grocery stores, gas stations and fast-food restaurants.

Cardholders receive 1% on every dollar spent for almost any other purchase and pay no annual fee.

Once you've earned $50, you can ask for a $50 check or -- better yet -- keep going and redeem $200 worth of rewards for $250 cash back.

By Carolyn Siegel

Interest.com Associate Editor

Have a question about your finances? Ask us at editors@interest.com.