I found myself liking most SatAM episodes and if there would be any episode I remember best from when I was a child it would have to be this one...though there are some other key episodes I remember from back then.
This was about Sally being captured by Robotnik during the Freedom Fighters raid on the swatbot factory. When Sonic and Bunnie make it back to Knothole to find that Sally hasn't made it back yet the realise that she must have been captured. Robotnik now having his hands on Sally desides to use that even more to his advantage and has made a robotic copy of Sally that he plans to use as bait for Sonic to uncover the location of Knothole.
This episode to me was the best episode that SatAM has to offer. It had a very good solid plot, was compelling, well writen and it probably had the best directing the show had and you could really feel the atmoshere. Aslo because this was in season 1 we didn't have to deal with the very irritating Dulcy....a must see episode.