Entourage Replacement

I am looking for an Entourage replacement application. Specifically a SINGLE application that integrates Apple Address Book, iCal and Mail or uses the databases for those three applications. I've seen a few on Version Tracker and MacUpdate but they were geared towards businesses and were very expensive. I prefer freeware but am willing to pay a modest amount for a good program with tight integration.

Thanks in advance for your suggestions.