I realized at some point that anthology series in comics are the ones I go back to and re-read more than just about anything else. Single-issue stories, compared to where a writer or artist can do 6 or 12 issues of a series like BATMAN or X-MEN or AVENGERS or PHANTOM STRANGER (much as I love them too), but can often show a far greater range of their talent in the same number of issues of an anthology book.
It was the range of Walt Simonson's talent displayed in just 4 random backup stories and pin-ups in STAR SPANGLED WAR STORIES (issues 170, 172, 174 and 180) that led editor/writer Archie Goodwin to pick Simonson to do the "Manhunter" series in DETECTIVE COMICS 437-443, that gained both of them instant acclaim and industry awards. I agree with Goodwin that this earlier Simonson material is pretty damn spectacular too.
https://readcomiconline.li/Comic/Star-Spangled-War-Stories-1952/Issue-170?id=155136#23
https://readcomiconline.li/Comic/Detective-Comics-1937/Issue-437?id=5679

I like anthology work, both by new artists and by more established and acclaimed ones, because it often reveals a whole new side of a well-known artist, taking their talent down another previously unseen path. And there are other artists who only briefly appeared in comics, but made wonderful contributions in just a few brief stories.
And others (like say, Frank Miller, Jerry Bingham, Bissette/Tottleben, Michael Golden, Keith Giffen, etc.) who did enjoyable anthology stories, and then went on to stardom doing better-known series work.

[Linked Image from milehighcomics.com]

I think I'll start off mentioning HOUSE OF MYSTERY as one of my all-time favorites, that presented a fantastic range of stories, introducing some of the earliest work by artists like Berni Wrightson (his first published work!), Neal Adams, Nestor Redondo, Ernesto Patricio, and Alex Nino, and great work by long established talents like Alex Toth, Jerry Grandenetti, Bill Draut, Gray Morrow, Wallace Wood, Sam Glanzman, Jim Aparo and others.
And then roughly a decade later HOUSE OF MYSTERY also became an early outlet for the greatness of Marshall Rogers, Michael Golden, Jerry Bingham, Arthur Suydam, Bob Layton, Don Newton and other great artists.

"The Devil's Doorway" by Toth, and "The Hound of Night" by Grandenetti, in 182 :
https://readcomiconline.li/Comic/House-of-Mystery-1951/Issue-182?id=70707#1
"Turner's Treasure" by Toth in 184 :
https://readcomiconline.li/Comic/House-of-Mystery-1951/Issue-184?id=70711#1
"Hunt for the Red Fox" in 187, another great Toth offering:
https://readcomiconline.li/Comic/House-of-Mystery-1951/Issue-187?id=70717#1


"The Beautiful Beast" by Al Williamson in 185 (after a long absence from comics. Williamson was one of Neal Adams' greatest influences getting into comics, it must have been a treat for him to draw the cover for Williamson's story. )
https://readcomiconline.li/Comic/House-of-Mystery-1951/Issue-185?id=70713#1

"Nightmare" by Adams, and "Secret of the Egyptian Cat" by Wrightson in issue 186.
https://readcomiconline.li/Comic/House-of-Mystery-1951/Issue-186?id=70716

One flash in the pan talent I love who only did about 20 stories in comics over more than a decade is an artist named William Payne, who did two outstanding stories in HOUSE OF MYSTERY 206 and 207, in 1972.
https://readcomiconline.li/Comic/House-of-Mystery-1951/Issue-206?id=70739
https://readcomiconline.li/Comic/House-of-Mystery-1951/Issue-207?id=70740

With other stories I enjoy as much by other writers and artists. The cover and intro splash page in 207 by Wrightson are gorgeous, and suitable for framing.

[Linked Image from 2.bp.blogspot.com]

The HOUSE OF MYSTERY run from 174-321 (1968-1983) offers a consistent parade of talent, pretty much to the end of its run. Somewhat diminished by the lower page count in the 1975-1980 period. But even in that period presented work by many of the talents I listed above, and either Kaluta or Kubert covers on the second half of its run, right up to the last issue.

So what are some of your favorite stories in HOUSE OF MYSTERY?
Or what other anthology series would you recommend?