Sunny and "the revolving Straight man"

I've been on a It's Always Sunny binge lately and what struck me as unique about this cast is the revolving straight man.

I figure we all know about the straight man concept used every single comedy duo (that I know of) but Sunny's straight man is never static. In season 1 you can see that all of the characters were more basic and realistic even by Sunny standards. Then season 2 brought in Danny D as the somewhat straight man with sweet Dee acting as such in various episodes.


Now it's a free for all and with great results I might add. Now you get alternating characters questioning the sanity of other characters almost willy nilly. Episodes like Mac and Charlie Die part 1 just show how fluid the situation is with this show.

We start with Mac deciding to fake his and Charley's death to escape the wrath of his dad. Charley instantly agrees that they should kill themselves. And the you get the funny situation of Mac trying to make Charley understand they are going to FAKE their deaths and not really kill themselves.
Next scene is Mac explaining the concept of running the car into a brick wall at 70 mph and jumping out "3 feet" from impact (I just laughed as I typed that). And Charley is now the sane one saying there is no way in hell hes going to do that.



But that's the beauty of Sunny. Each character goes crazy in their own way. Charley never gets the big picture or abstract concepts. Mac will always try some rediculous physical feat or absurdly boast about his physical prowess. Dennis has become an obvious sociopath. Frank and Dee are funny in various roles.



I bring this all up because I was trying to think of another show where the revolving straight man was played so well and I admit I have limited knowledge. Anybody have another show comparable?