This is what sometimes happens when you're a student and you've only got enough money to live in a dingy hovel... you get a landlord like Rigsby. What few standards he has are outdated, so sensitive lads with long hair and intelligent young black men are almost too much to take. Leonard Rossiter's portrayal of a character who could easily be completely beyond redemption is absolutely pitch-perfect. The more episodes you watch, the more you find yourself becoming strangely endeared to his mannerisms and tics, despite the fact that his attitude makes him a thoroughly unpleasant man. Aside from superb comic timing, Rossiter was also a master of the pratfall, so some of the most memorable sequences owe a lot to slapstick (I'm thinking particularly of the arranged boxing match.)
It isn't quite a one man show though. All of the supporting parts were perfectly cast, so even when someone like Don Warrington pops up in more modern fare such as "Red Dwarf", he's still likely to be instantly associated with playing "Phillip" in "Rising Damp". I can't think of a bad episode in the bunch that I've seen. All of the scripts are so polished that they gleam, and this combined with the acting talent is what makes the show stick in the memory as the loved favourite it is.