Big fan here. I didn't really watch it as religiously once it moved to Sci-Fi, though, since for one, I don't believe in waking up early on Saturdays, and also things weren't the same without Dr. Forrester. Furthermore, Ortega was a poor substitute for Torgo.
Some of my favorites were:
Manos- of course
the Russian movies- Jack Frost, Day the Earth Froze, and Sinbad
Pod People- "Trumpy, you can do stupid things!"
Fugitive Alien- mainly because it was the first one I got to see. Still fun, though.