Edit 01-15-2014: After rebuilding my htpc a couple times it's become clear that these settings are arbitrary at best. I just have to trial and error the settings every time.
Windows media center has cryptic terms for how recordings are set.
1. To record three episodes of a show, recording every time, keeping the most recently aired shows:
Show type: New & rerun
Channels: any
Airtime: Anytime
Keep: Until space needed
Keep up to: 3 recordings
Stop: 3 minutes after, when possible
2. To record three episodes of a show, only recording when one has been deleted. So in effect, there will always be 3 shows available, but some might be old. This is good for something like Wheel of Fortune that it's nice to have a couple, but you don't want the PC starting up all the time to record new episodes. The "Latest recordings" setting seems opposite of what you want, but that's the setting to keep older shows and not have WMC discard a show to record a new one.
Show type: New
Channels: any
Airtime: Anytime
Keep: Latest recordings
Keep up to: 3 recordings
Stop: 3 minutes after, when possible
3. To keep as many as possible, and not discard any shows to record new ones (for your favorite show).
Show type: New & rerun
Channels: any
Airtime: Anytime
Keep: Until I delete
Keep up to: As many as possible
Stop: 3 minutes after, when possible
