NFS, AFP, SMB... Advantages and drawbacks on a Mac OS system
Essentially, NFS is the Unix way of doing network shares, AFP is the Apple way, and SMB/CIFS (they're basically the same thing) is the Microsoft way. AFP will generally work best with a MacOS system (except that most third-party implementations are currently struggling to catch up with a change made in Lion where an older and less secure authentication method was dropped) because it's better integrated with OS X authentication and with Time Machine.