I'd call him the John Sullivan of ITV comedy. Anyone else agree?

Depends if you're talking about his range, his volume, or his style.

Just in terms of number of great shows he has written. Underrated I feel. Most people know his shows but not that he was the creator.

Ah. Well then yes, I suppose that's not too unfair a comparison to make.

Yes, top writer, Rising Damp is a master-piece, Only When I Laugh and The Bounder were also top sitcoms, Duty Free was all right but I wasn't a big fan of Home to Roost. I'd be interested to see his first sitcom 'The Squirrels' get released on DVD, as I've not seen it. When I bought The Bounder on DVD, I knew it was by Chappell, so I didn't hesitate, got it home and laughed hysterically through many episodes which is quite rare for me.

He also wrote Singles, Fiddlers Three (a Squirrels remake I believe) and Haggard.