The best quality would be to keep the recorded signal digital, avoiding analog conversions using composite, s-video, or component inputs/outputs.
There are a number of HDMI capture cards/USB boxes available for PC. However, as mentioned, HDMI cable signals require the use of HDCP copy protection. So cannot capture/record these to a PC without using a secondary splitter that effectively strips HDCP. However, this is likely breaking DMCA by circumventing digital rights management.
Time shifting has been deemed legal for recorders such as DVR, which require the use of a licensed device, current copyright exemptions may not allow for space shifting the same content - or converting to another format? Though there are exceptions. Not to mention, digital copyright owners have tended to go after manufacturers of circumvention devices/software. Not the non-commercial end user.
