There's a whole slew of them out there. You probably just need to look at what you'd want most in terms of freebies. Do you want miles, vacation points, miscellaneous goodies, brand credits, straight cash, etc. Most people like straight cash or frequent flyer miles.
I don't fly all that much and while I certainly don't mind getting cash back you have to be willing to charge a ton to get an appreciable amount back. I've personally been using the Marriott Rewards Visa card over the last year. I think it has something like a $30 annual fee and I don't know/care what the interest rate is. We pay our card off each month anyway and always stay in good standing. I figure this way we can build up points to something you don't usually allocate money for in your monthly budget, vacations. They naturally offer tie-ins to frequent flyer and rental car programs (nearly all cards like this do) but I like the idea of being able to periodically cash in my points for an extended weekend somewhere without having to think about paying for it. In fact, they just upgraded our account to Visa Signature service which has a few additional perks I'll probably never use. But that also means I get 10,000 points just for staying in good standing. So that's practically another free night if we need it.
Hilton has a similar program (with actually better earning potential I think, but I'm too far in now to change) as do all the major hotel chains. I'm currently in the process of trying to make our mortgage payment each month with this card. Since we have a credit line with lots of headroom and pay off our bill each month anyway we might as well use a major monthly expense towards building up our points.