The Best Silver Age Spider-Man Story Arc
Things go from bad to worse as Aunt May slips into a coma. Then Peter Parker learns that he himself may be responsible for her condition. In desperation he turns to one of his old foes, Dr. Connors (AKA The Lizard) for help. But no sooner do they find a potential cure than The Master Planner's men steal it. Spider-Man goes on a rampage through the New York underworld in search of The Master Planner. And when he learns The Master Planner's true identity, it turns into all-out-war.
This is without a doubt one of the best issues of The Amazing Spider-Man from the Silver Age. It's part two of a multi-part story that has Spider-Man pushing himself to his absolute limit. Not only is it one of the best from a writing standpoint, but Steve Ditko's artwork has dramatically improved of late, particularly his ink work which gives the characters a more three dimensional look than some of his earlier work.
If you had only a handful of Spider-Man issues you could read, this ought to be among them!