Eva's Back in Town is another good one with Alvin.
one of my earliest crushes Shirley Anne Field admired her ever since I first saw Saturday Night Sunday
I enjoyed Whatever Happened to the Horse? (Series 28) Seeing Alvin fully committed to the comic shenanigans never fails to amuse.@David Piper, like most of the later characters he was initially cast as a one off barmpot character, I'd suggest that would be a good place to start. The episode is The Lair of The Cat Creature and is very funny!
Roy also featured in Man about the House too.If you get the chance to see George & Mildred give it a watch. There’s some great episodes and one of my favourites Roy Kinnear appears in a few.
The 26 year Itch is one of my favourites.