Uh...no; flashback episodes (i.e. "clip shows") go straight to the bottom of any episode list. The only exception to the aforementioned rule is if an episode features entirely new flashbacks.
As I said, there have been some clip shows in more recent decades that have been very worthwhile. I consider "Who Is Superboy?" to be one of the best episodes of the
Superboy series.
Andromeda's "The Unconquerable Man" is one of the best episodes of its third season, though a lot of that season is utterly dreadful.
After all, a clip show isn't
just clips. What differentiates a good one from a bad one is what the new material (the envelope, thanks for the name,
Maurice) is like. Is it just an excuse to set up the reminiscences, or does it tell a meaningful story of its own that has actual relevance to the series's plot and character development? The clip shows that rise above the pack are the ones that manage to do the latter, like the ones I mentioned or
Stargate episodes like "Disclosure."
Hercules and
Xena had fun with their clip shows, making the envelopes really crazy and bizarre a lot of the time. The archetypal one is "Yes, Virginia, There Is a Hercules," in which the cast members and recurring guests of
Hercules: The Legendary Journeys played the producers and writers of
Hercules: The Legendary Journeys as grotesque caricatures of themselves (e.g. Bruce Campbell played Rob Tapert and Ted Raimi played Alex Kurtzman) -- with the conceit being that Kevin Sorbo was actually the real Hercules pretending to be an actor named Kevin Sorbo playing Hercules on TV. (Okay, that part has aged very poorly.) A lot of their clip show envelopes were set in the present day (presumably to save money), often involving lookalike reincarnations or clones of the series leads.
One clever twist was in
Xena's first clip show, "Athens City Academy of the Performing Bards." They used clips to represent the stories told by the various bards, but while Gabrielle's stories were clips from
Xena/Hercules episodes, the other storytellers' clips were taken from Steve Reeves Hercules movies and even Kubrick's
Spartacus (even though that should've happened quite a few centuries after
Xena, but these shows always played incredibly fast and loose with chronology, with everyone from Helen of Troy to Julius Caesar to Dracula being contemporaries of each other). So they were basically having fun with the formula of a clip show, confounding our expectations of what the clips would be.