Well, I can think of at least two pre-2005 TV non-studio audience comedies, besides Scrubs and Arrested Development, that didn't use a laugh track - Malcolm in the Middle and The Bernie Mac Show. All of these shows lasted for several seasons too. As far as the animated comedies, I'd point out that The Flintstones and many of the cartoon comedies of the 1960s and 70s used laugh tracks so the decision by the current animated producers to go without was a break from tradition, not a continuation of one.
Now as far as non-studio audience TV comedies that use a laugh track, I don't recall any over the past couple of decades. I Dream of Jeannie and Bewitched may have been the last. Any more recent?
To bring this back to Jack Benny, I remember an interview with Fred De Cordova who produced and directed many of Jack's television shows before moving on to The Tonight Show with Johnny Carson. De Cordova mentioned how Jack used the non-studio audience/laugh track approach with increasing frequency during the latter years of the show and that, in place of the audience's response to time his reactions, Jack relied on the director counting off "laugh, laugh, laugh" for his timing. I can't imagine though that it worked as well as when he had the audience.