Adam West batman, Get Smart, and 60's spiderman (which has heavy involvement of the Wayne and Shuster support team) are pretty much a given.
but for me, it was the following shows:
Rocket Robin Hood
A Bear called Jeremy (which besides being my earliest childhood memory, had a metaplot :p)
The Mighty Hercules (with the single greatest monster sound of all time. Pity they kept recycling it).
Max 2000 year old mouse
Batfink and Karate (excuse the racism)
The Original Mighty Mouse
The Wonderful Stories of Professor Kitzel
The Friendly Giant
Wayne and Shuster (also known as awesome)
What are the shows you remember from the dawn of your existence?