Dvr+ hdd PVR (set top box) - anyone out there with a good working knowledge of current models? Which is best?

I want to buy a dual tuner hard disk recorder with dvd recording for my elderly father as his old vhs has given up the ghost. He's always been good with electronics (hi-fi nut), but is lacking confidence with some of the newer technology. Can anyone suggest a really good unit thats relatively straightforward to use?