37Signals

The Good:
Highrise app is simple. You and your team can be up and running in no time, and will have a wonderful client/contact manager that is web based. The interface is friendly, information is easy to locate and update, and its a great app if all you want to do is have records of conversations with your customers, along with their contact info. Calendar and Task applications are also handy.
The Bad:
The app is too simple. There isn't much you can do to customize it. As your contacts grow in size and complexity, you are left with a dental floss when you really need a tow rope. You can't even make a contact record that has a husband and wife with different last names! The search option is a bit finicky and doesn't always get you the results. Email integration is cumbersome and dated with limited scope.
The Ugly:
You may find out the shortcomings of the applications after its too late to do something about it. I mean once you've entered 500 clients in the app, and have been using it for a few months, its difficult to just abandon it and go to some other platform.