Up until very recently, I've been watching Last of The Summer Wine every day but I've been giving it a bit of a rest for the past week or two. I try to watch any episode of Air Crash Investigation that I've not seen before and I similarly tend to watch Murder on CCTV and Murder Come to Town.
Other than that, there aren't that many programmes that I watch regularly. (I probably watch far less telly than most people do).
However I've found some excellent programmes on BBC Alba (from history programmes through to canal journeys, etc). The fact that they're in Gaelic doesn't matter, as they're always subtitled in English. BBC Scotland also has some good programming, especially Stand Up for Live Comedy.