It was after the second season, they brought it back for a third. I believe.
The only show that comes to mind is Rosewell. But I am not even sure the show was canceled at first, just more like it was going to be canceled and they didn't do it.
I believe SNL was close to being canceled (I think in 1980, 1981 and 1985; Jean Doumanian, Dick Ebersol and finally the return of Lorne Michaels saved each season respectively), as was Chappelle's Show.
I don't know if it WAS cancelled or was on the brink of cancellation, but would this little program from the '60s about "boldly going where no man has gone before" or something count?
I didn't say I got them all. That counts.