The Abe Lincoln episode was titled The Savage Curtain. It was a 3rd season episode, and one of the worst. The 3rd season was the last, and it was generally terrible, but there were a few decent episodes.
Right up there with “Spock’s Brain”
My favorite episodes were generally the ones with Klingons, Romulans and Harcourt Mudd.
There really were some excellent ones and most of the ones with a bit of humor were also good. I also liked the recurring theme of very simple people under the control of some computer etc.
It took me a while to get back into ST after
watching the Spocks Brain episode.
Kinda like the last year of Wild Wild West.
Ran out of good ideas I thought at the time