The ones I read the most are:

(1) Dr. Strange, Vol. 1
(2) Dr. Strange, Vol. 2 (Ditko issues only)
(3) Atlas Era Venus
(4) Atlas Era Sub-Mariner (plus Subby stories in other Heroes volumes)

Plus, sort of randomly, so it's hard to rank them: 
(5) Anything with Ditko artwork
(6) Anything with Kirby/Stone artwork
(7) Atlas Era Jungle Adventures (all of them)

Anarchy and Chaos are the natural state of the human race. Civilization is unnatural. It is a whim of circumstance. And Chaos must always ultimately triumph.