Don't know if I could pick a single episode.Among my favorites were....
TRICK OR TREAT-the pilot.Always loved Barnard Hughes (TRON,MR. MERLIN) as the baddie.
INSIDE THE CLOSET -Just a good,creepy outing with another actor I always liked,Fritz Weaver (CREEPSHOW,DEMON SEED).
HALLOWEEN CANDY-One of Tom Savini's early directing credits.
THE CUTTY BLACK SOW-A slow burner,with a very nice script by Michael McDowell (BEETLEJUICE).
DISTANT SIGNALS-A TWILIGHT ZONE style episode with KOLCHAK himself,Darren Macgavin.
SEASONS OF BELIEF-Another slow burner,very blackly comic,with a memorable payoff.
MISS MAY DUSA-A rarity for the series,a tragic love story,offbeat.
THE MOTH-A moody witchcraft tale with Debbie Harry (who later starred in the wraparound segment of the movie).Former Blondie guitarist Chris Stein did the score.
There were certainly some bad episodes and the low budget often showed through but at it's best it was a very fun little show.I miss it.