I second that.
I just got a Nova-T DVB card, and have been playing about with mediaportal for the last couple of days. Loving it so far.
GBPVR is another freeware (though not open source) program. Unfortunately I had some problems tuning in channels with this, although it looks promissing.
Mediaportal has a very nice UI, but must be running permanently for scheduled recordings.
GBPVR, by comparison, appeared to have a tray icon that could run in the background when recordings where scheduled, without having to have the main app running - a more elegant solution for a machine that is not a dedicated HTPC.