ABC’s ‘Nightline” had its best Total Viewer average in nearly a year last week, but it still wasn’t enough to maintain the program’s first-place streak against CBS’ “Late Show” and NBC’s “Tonight” show. David Letterman, now in the news for quite a different matter, had one of his strongest ratings weeks in some time and his weekly average was up 30% from the same week last year. Of course, it always helps to have President Obama and President Clinton come by your show the same week.

The numbers for the week of Sept 21: