We had a ReplayTV 2020 back in 1999, and loved it. I always thought ReplayTV was better than TiVo, but TiVo had a lower sticker price with a subscription, and consumers are dumb. We moved to MythTV when we got an HDTV in 2004, recording off of antenna and QAM, later getting a HDHomeRun with CableCard. Last year we dropped cable, as we had mostly stopped watching it in favor of streaming, so MythTV still is sitting there recording occasionally from the antenna, but we rarely use it.
As far as features go, though, MythTV was the best I've seen for recording TV. It's a shame it's a bit complicated to set up; I believe someone tried selling preconfigured boxes at one point, which would have been a great idea, but there were issues with the TV listings.
For people who still want to record TV and are geeky enough to be here, MythTV is still a good option, though you'll need CableCard support from your cable company, and some of the channels will have copy restrictions so you can't record them.
But for everyone else, most cable companies will provide a DVR service of some sort (usually now streaming from their servers, not really recording locally), so you're pretty much stuck with that.