M*A*S*H, but only up to when Frank Burns left. After that, the show was unwatchable. Even Klinger became annoying when he dropped women's clothing and started wearing a Toledo Mud Hens jersey and cap.
Some other comfort shows: Barney Miller, Cheers (the first several seasons), Taxi, The Honeymooners (the original 39), Combat!, Twelve O'clock High, Homicide, Life on the Street (why isn't this great show streaming anywhere???), Streets of San Francisco.
Seinfeld had a great run but the last few seasons were painful. George becomes more annoying in each rerun...the only saving grace during those years was Jerry Stiller.