I've watched so many British comedies - Allo Allo, Are You Being Served, etc. etc. but this one always had a special place in my heart.
What's different about this sitcom, is that it feels far more real and far less a parody on the real world than so many other sitcoms. The way the servants live a strict life with a daily routine to go through, not to mention that more serious matters are not brushed aside. The characters have more depth as a result and feel very fleshed out.
The way you feel sad for Mabel but then happy when she finally gets some luck coming her way. Or the crush of Ivy for Twelvetrees who always brushes her off. It's not a typical British sitcom, no, but I wouldn't have it any other way. The romantic representation of the 20's (and also a glimpse at the not-so-romantic side) give it extra flair not to mention the high quality of the decor and the outfits!