There are many choices out there including SMB (slow), NFS (a hassle since if you are Windows user then there is no native NFS support in Windows without going to the trouble of installing Windows Network Services for Unix or some third party product, and http.
I started with SMB but found it slow. Then moved to http via MyiHome but found that a bit flaky also. I now use Swisscenter which I had been using on my Pinnacle SC1000. It's free and now has PCH support and works really well. It apparently has resume support (though not quite working yet) which the PCH does not have.
If you are daring you can also using gbpvr but from reading the docs on how to do that, I might stay away from it. But it looks like the most fully functioned since it allows you to control your gbpvr installation on the PC for not only watching but also recording video shows.