Usually, it's more fun when three girls tear your suit off.

This one takes you on a ride--maybe not in an entirely satisfactory manner, but it hits a lot of notes. From 1970, Superman #223, "Half a Hero!" Written by Cary Bates, pencils by Curt Swan, inks by George Roussos.

Clark finds himself compelled to visit a nondescript restaurant, where the waitress thanks Superman for stopping by; then as he watches a pop star mobbed by fans at the airport, one locks eyes with him and says "Nice to see you here, Superman!" which no one else can here. Later, at a movie, when Superman appears on a newsreel (did they have those in the 70's?) an usher compliments him for looking great on film. Clark is then abducted by a flying saucer, and his suit exploded off of him, by the three girls, who introduce themselves at the Galactons, a club of super-heroines; that was looking for a new member--their first male member. (Cue "bow chicka wow wow" music!) The girls also have the same speech patterns as Huey, Dewey, and Louis; as one of them starts a thought in the panel, that will be picked up by the next one, then maybe finished by the third. This tryout is a riff on the old Legion of Super-Heroes origin, although it isn't acknowledged as such, except a mention that he belonged to that club as a kid. (Club membership, for children and adults, was a lot more prevalent back then; although I think it had faded a lot by the time I was a kid and is virtually unknown now, unless everybody's in a secret club without me!)

Superman's tryout for the Galactons goes awry, as he's taken to a distant planetoid, to tame a "Mumox." Instead, the Mumox gases Superman, knocking him out: he wakes up, hooked up to machines on the Galactons' ship, and the girls have bad news: the gas had not only nearly killed him, but it had permanently crippled him, leaving him unable to leave earth's yellow sun. Superman is furious, feeling like his effectiveness had been reduced by 50%; but it might've been more than that? Lotta not-yellow stars in space; and now Supes would still be able to see them in trouble, but would be unable to help.

The next day, a "defective" Superman-Robot poses as a shoeshine man and gives Perry White a hotfoot, in an elaborate scheme to get a warning to Superman: Superman isn't thrilled with the bot, and plans to scrap it later, but it was trying. A weird, giant, hypodermic needle-looking thing, is injecting weird crystals into the earth: no one else seems to have noticed earth getting a fix. Supes finds the crystals have lodged in the earth's core, and they were growing: left unchecked, they would destroy the planet in short order. Superman goes to the Galactons for help, presuming the girls could project x-rays (which seems presumptuous, but there's a reason!) and together they destroy the crystals with a massive blast of x-rays. The Galactons seemingly knew about the crystals, and their leader has something to tell Superman, who cuts them off: take off the mask, Supergirl! While there's other oddness here, I was wondering why the other two Galactons were also masked: they were from Kandor, but would Superman know every girl there...? Well, maybe.

Superman rather brusquely cuts them off, since it was "R-Day" in Kandor, and here's where this starts to feel like 20 pounds of plot in a 10-pound bag. He flies back to the Fortress of Solitude, and uses the "micro-wave tunnel" device to shrink down to visit the city. Which was also being hit, by the crystal menace! Supergirl finally explains: when the crystals started wrecking the bottle city, the Kandorians thought they were done for, but didn't want Superman to die with them, so they made up an elaborate hoax with the Galactons to convince Superman he couldn't live under a red sun. Then, Supergirl had the idea of duplicating the menace, with artificial crystals that wouldn't have done any harm, and Superman figured out how to stop them and now they could save the city. Except, they need super-x-rays, and the assorted trips back and forth had drained the micro-wave tunnel's power, so Superman and Supergirl couldn't get back under earth's yellow sun, and Kandor was doomed! This is why honesty is the best policy, kids. 

Despite the city being doomed, R-Day apparently stood for Release-Day, as the Kandorian Parole Board was going to release some prisoners from the Phantom Zone, as their sentences were up. The prisoners aren't particularly grateful: as one puts it, "I didn't spend 30 years in the Zone just to die the first day I'm out!" Superman notices another Phantom Zoner, who still had time on his sentence: Gor-Mu, a bio-chemist who caused several deaths with reckless experiments. Could Gor-Mu save Kandor? Maybe, but he has a condition: he wants to switch bodies with Superman! This seems like a problem, but relax, there's only two more pages in the issue; it all turns out.