Aunt May
Real name: May Reilly Parker.
First appearance: Amazing Fantasy 15.
Died in: Amazing Spider-Man 400. She went out with dignity and grace; wasn't thrown off a bridge, wasn't menaced by a super-villain, wasn't ripped through an inter-dimensional portal and returned as a demon, wasn't a clone. (Pretty much the last of the Spidey stories worth anything, in fact, and surrounded by ones that were definitely lack-luster...but that's just me...)
Team affiliation: While she was an active member of the Gray Panthers until her failing health forced an end to her protesting days, May's family, consisting of her late husband, Ben, and her orphaned nephew, Peter, always came first. May also had strong feelings for Doctor Octopus (yes, the Doctor Octopus), whom she always thought was a dear, dear man, and who was very fond of her as well. She came very close to marrying him, but believed him lost when her inheritance and dowry (an atomic breeder reactor in Canada) blew up with him in it on her wedding day. Later she would become engaged to Nathan Lubensky, who died protecting her from the Vulture. For a long time, May dealt with the weirdness in her life by inventing fantasies about the odd things that seemed to occur around her -- she pretended the police were jealous of Doc Ock and persecuted him for his genius; pretended that Gwen Stacy's death was just a rumor so that she wouldn't have to deal with the idea of a Gwen Stacy clone; and pretended Spider-Man was a horrible, horrible thing so that she wouldn't have to deal with the consequences of...well, the truth. Shortly after Spider-Man saved her from the Burglar in Amazing Spider-Man 200, May began to come around, even telling her friend Anna Watson that Spider-Man wasn't so bad. May finally came to grips with her dislike of Spider-Man shortly before her death, realizing that she'd always associated the murder of her husband with the appearance of the new super-powered guy on the block. From there, it was just one more step to admit to herself what she had always subconsciously known -- that her frail, bookish nephew was Spider-Man.
Favorite quote: "You should be ashamed of yourself, young man. I haven't a very high opinion of Spider-Man ... but at least he has manners." (Amazing Spider-Man 146. The "frail and fragile" Aunt May tears a strip off of the super-villain Scorpion after he trashes her hospital room. And there's the time she told her over-protective nephew he should get more "hep." She meant, of course, "hip.")
Abilities: May had the best cold cure in the Western Hemisphere; lots of fluids and bed-rest. Doctors still prescribe that for colds!
Favorite storyline: Amazing Spider-Man 220. Aunt May serves cookies to a punk rock band, trips the light fantastic until the wee hours, solves a mystery and traps a thief -- all without involving Peter, who was just too frail to be told the truth about his Aunt's exciting life...
Least favorite storyline: May as the weak, frail, elderly aunt with a grudge against Spiders became a tired plot point fast; early on in the Amazing Spider-Man books, she was often shipped off to Florida or other places so that Peter could have adventures without her hanging around. It was quite a while before she began to develop a personality apart from just being Peter's aunt, and more than one hundred issues into the run before she began to develop the spunk and good sense that became her trademarks. Her "failing health" was finally corrected with a coronary by-pass operation.