In addition to Restaurant City, Bejeweled and Guitar Geek, I am now hooked on Cafe World and Happy Aquarium on Facebook.
At first, I didn't like Cafe World. You actually had to pay attention to it, it was high maintenance. You had to make sure you kept track of the cook times lest the food goes stale before you log back in to move it to the counters for serving. In RC, you had to make sure your staff don't get too tired. In CF, you may run out of food to serve. The good thing with RC is that you can block the door and that will allow you to close shop for the day, until you log back in to FB. In CF, there's no closing shop. So stock up on enough food to serve until your next log in. Or cook something that takes 24 hours to cook so it will be there when you login the next day.
I'd love to post screenshots, but Cafe World keeps timing out on me. They seem to be having server issues - something very inconvenient!